SmogRank / Episodes / Thailand
Thailand and Laos, April and May 2024
For 9 days, from 29 April to 7 May 2024, 45 cities in Thailand and Laos had PM2.5 at least twice their usual for the time of year. The worst reading was Ban Houakhoua, Bokeo, Laos: 237.0 µg/m³ on 2 May, about 7.0× its usual 33.7.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 45 in 2 countries
Days 9 29 April to 7 May 2024
Worst day 2 May 34 cities counted
Furthest above usual 7.2× Chiang Rai
Day by day
Play 2 May 34 cities at twice their usual or more
Si Maha Phot Nong Chok Bang Bo District Lat Krabang Ban Talat Bueng Aranyaprathet Khlong Sam Wa Khan Na Yao Bang Na Bang Kapi Sai Mai Rayong Khlong Luang Lak Si Ban Chang Phra Pradaeng Saraburi Chanthaburi Bang Khun Thian Samut Sakhon Nakhon Ratchasima Lop Buri Trat Suphan Buri Sing Buri Buri Ram Kanchanaburi Chai Nat Khon Kaen Yasothon Tha Bo Mae Sot Surat Thani Nakhon Si Thammarat Trang Hat Yai Yala Satun Narathiwat Betong Ban Khlong Prawet Surin Nong Khaem Ban Samae Dam Bangkok Nakhon Sawan Roi Et Vientiane Phra Nakhon Si Ayutthaya Mueang Nonthaburi Chaiyaphum Amnat Charoen Mukdahan Laem Chabang Ratchaburi Nakhon Nayok Nakhon Pathom Phichit Nan Sukhothai Kalasin Phuket Hua Hin Kamphaeng Phet Samut Prakan Sakon Nakhon Si Sa Ket Phetchabun Udon Thani Ubon Ratchathani Pattani Phetchaburi Loei Lampang Phrae Lamphun Nong Bua Lamphu Pakxan Chiang Mai Ranong Phayao Uttaradit Mae Sai Ban Houakhoua Chiang Rai 26 Apr 27 28 29 30 1 May 2 3 4 5 6 7 8 9 10 Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.
How it spread
Ban Houakhoua Ban Houakhoua, 26 April: no reading Ban Houakhoua, 27 April: 90.3 µg/m³ Ban Houakhoua, 28 April: 108.0 µg/m³ Ban Houakhoua, 29 April: 151.0 µg/m³, 4.2× its usual 36.3 Ban Houakhoua, 30 April: 148.0 µg/m³, 4.2× its usual 35.6 Ban Houakhoua, 1 May: 164.0 µg/m³, 4.7× its usual 34.8 Ban Houakhoua, 2 May: 237.0 µg/m³, 7.0× its usual 33.7 Ban Houakhoua, 3 May: 177.0 µg/m³, 5.6× its usual 31.6 Ban Houakhoua, 4 May: 110.0 µg/m³, 3.8× its usual 29.1 Ban Houakhoua, 5 May: 145.0 µg/m³, 5.2× its usual 27.8 Ban Houakhoua, 6 May: 124.0 µg/m³, 4.5× its usual 27.4 Ban Houakhoua, 7 May: 114.0 µg/m³, 4.3× its usual 26.7 Ban Houakhoua, 8 May: 55.2 µg/m³ Ban Houakhoua, 9 May: 62.9 µg/m³ Ban Houakhoua, 10 May: 48.8 µg/m³ Phayao Phayao, 26 April: 55.2 µg/m³ Phayao, 27 April: 54.9 µg/m³ Phayao, 28 April: 88.5 µg/m³ Phayao, 29 April: 87.9 µg/m³, 2.8× its usual 31.7 Phayao, 30 April: 79.3 µg/m³, 2.5× its usual 31.3 Phayao, 1 May: 84.3 µg/m³, 2.7× its usual 31.3 Phayao, 2 May: 105.0 µg/m³, 3.5× its usual 30.1 Phayao, 3 May: 85.2 µg/m³, 3.1× its usual 27.3 Phayao, 4 May: 74.7 µg/m³, 2.9× its usual 25.7 Phayao, 5 May: 66.7 µg/m³, 2.7× its usual 24.3 Phayao, 6 May: 73.8 µg/m³, 3.1× its usual 23.8 Phayao, 7 May: 80.1 µg/m³, 3.4× its usual 23.4 Phayao, 8 May: 44.9 µg/m³ Phayao, 9 May: no reading Phayao, 10 May: no reading Nan Nan, 26 April: 71.2 µg/m³ Nan, 27 April: 68.6 µg/m³ Nan, 28 April: 82.6 µg/m³ Nan, 29 April: 86.8 µg/m³, 2.1× its usual 41.2 Nan, 30 April: 80.4 µg/m³, 2.0× its usual 39.9 Nan, 1 May: 81.5 µg/m³, 2.1× its usual 39.7 Nan, 2 May: 87.6 µg/m³, 2.3× its usual 38.5 Nan, 3 May: 74.0 µg/m³ Nan, 4 May: 50.4 µg/m³ Nan, 5 May: 61.7 µg/m³ Nan, 6 May: 68.1 µg/m³ Nan, 7 May: 67.3 µg/m³ Nan, 8 May: 49.6 µg/m³ Nan, 9 May: 41.2 µg/m³ Nan, 10 May: 43.6 µg/m³ Lampang Lampang, 26 April: 66.3 µg/m³ Lampang, 27 April: 61.4 µg/m³ Lampang, 28 April: 71.4 µg/m³ Lampang, 29 April: 82.3 µg/m³, 2.2× its usual 37.9 Lampang, 30 April: 72.2 µg/m³ Lampang, 1 May: 62.7 µg/m³ Lampang, 2 May: 95.3 µg/m³, 2.8× its usual 34.2 Lampang, 3 May: 94.4 µg/m³, 2.8× its usual 34.1 Lampang, 4 May: 64.1 µg/m³ Lampang, 5 May: 55.9 µg/m³ Lampang, 6 May: 67.7 µg/m³, 2.0× its usual 33.2 Lampang, 7 May: 78.3 µg/m³, 2.4× its usual 33.2 Lampang, 8 May: 38.5 µg/m³ Lampang, 9 May: 37.7 µg/m³ Lampang, 10 May: 31.6 µg/m³ Mae Sai Mae Sai, 26 April: 46.4 µg/m³ Mae Sai, 27 April: 50.1 µg/m³ Mae Sai, 28 April: 64.4 µg/m³ Mae Sai, 29 April: 75.3 µg/m³, 2.1× its usual 35.6 Mae Sai, 30 April: 79.1 µg/m³, 2.3× its usual 33.9 Mae Sai, 1 May: 87.3 µg/m³, 2.7× its usual 32.6 Mae Sai, 2 May: 121.0 µg/m³, 3.9× its usual 31.2 Mae Sai, 3 May: 92.1 µg/m³, 3.0× its usual 31.0 Mae Sai, 4 May: 66.9 µg/m³, 2.2× its usual 30.2 Mae Sai, 5 May: 84.9 µg/m³, 2.8× its usual 29.9 Mae Sai, 6 May: 78.6 µg/m³, 2.7× its usual 29.5 Mae Sai, 7 May: 77.8 µg/m³, 2.7× its usual 29.1 Mae Sai, 8 May: 54.9 µg/m³ Mae Sai, 9 May: 44.8 µg/m³ Mae Sai, 10 May: 31.0 µg/m³ Chiang Rai Chiang Rai, 26 April: 44.4 µg/m³ Chiang Rai, 27 April: 42.7 µg/m³ Chiang Rai, 28 April: 56.4 µg/m³ Chiang Rai, 29 April: 72.4 µg/m³, 2.6× its usual 27.8 Chiang Rai, 30 April: 68.6 µg/m³, 2.5× its usual 27.0 Chiang Rai, 1 May: 70.4 µg/m³, 2.7× its usual 25.9 Chiang Rai, 2 May: 128.0 µg/m³, 5.2× its usual 24.7 Chiang Rai, 3 May: 104.0 µg/m³, 4.3× its usual 24.3 Chiang Rai, 4 May: 86.6 µg/m³, 3.9× its usual 22.2 Chiang Rai, 5 May: 154.0 µg/m³, 7.2× its usual 21.4 Chiang Rai, 6 May: 130.0 µg/m³, 6.3× its usual 20.8 Chiang Rai, 7 May: 98.4 µg/m³, 4.7× its usual 20.8 Chiang Rai, 8 May: 72.1 µg/m³ Chiang Rai, 9 May: 33.6 µg/m³ Chiang Rai, 10 May: 23.3 µg/m³ Pakxan Pakxan, 26 April: 50.7 µg/m³ Pakxan, 27 April: 51.9 µg/m³ Pakxan, 28 April: 64.2 µg/m³ Pakxan, 29 April: 71.5 µg/m³, 2.9× its usual 24.6 Pakxan, 30 April: 62.0 µg/m³, 2.6× its usual 24.2 Pakxan, 1 May: 73.4 µg/m³, 3.1× its usual 24.0 Pakxan, 2 May: 61.7 µg/m³, 2.9× its usual 21.1 Pakxan, 3 May: 55.2 µg/m³, 2.7× its usual 20.1 Pakxan, 4 May: 32.3 µg/m³ Pakxan, 5 May: 39.4 µg/m³, 2.1× its usual 18.9 Pakxan, 6 May: 35.8 µg/m³ Pakxan, 7 May: 24.5 µg/m³ Pakxan, 8 May: 22.3 µg/m³ Pakxan, 9 May: 23.2 µg/m³ Pakxan, 10 May: 24.9 µg/m³ Chiang Mai Chiang Mai, 26 April: 79.9 µg/m³ Chiang Mai, 27 April: 71.3 µg/m³ Chiang Mai, 28 April: 68.2 µg/m³ Chiang Mai, 29 April: 70.2 µg/m³, 2.3× its usual 29.9 Chiang Mai, 30 April: 79.1 µg/m³, 2.8× its usual 28.4 Chiang Mai, 1 May: 73.2 µg/m³, 2.8× its usual 26.1 Chiang Mai, 2 May: 81.2 µg/m³, 3.2× its usual 25.3 Chiang Mai, 3 May: 65.1 µg/m³, 2.6× its usual 24.8 Chiang Mai, 4 May: 75.7 µg/m³, 3.2× its usual 23.4 Chiang Mai, 5 May: 73.0 µg/m³, 3.3× its usual 22.3 Chiang Mai, 6 May: 79.7 µg/m³, 3.7× its usual 21.8 Chiang Mai, 7 May: 76.9 µg/m³, 3.6× its usual 21.5 Chiang Mai, 8 May: 41.2 µg/m³ Chiang Mai, 9 May: 34.3 µg/m³ Chiang Mai, 10 May: 25.5 µg/m³ Nong Bua Lamphu Nong Bua Lamphu, 26 April: 31.4 µg/m³ Nong Bua Lamphu, 27 April: 36.0 µg/m³ Nong Bua Lamphu, 28 April: 38.8 µg/m³ Nong Bua Lamphu, 29 April: 43.3 µg/m³, 2.1× its usual 20.8 Nong Bua Lamphu, 30 April: 46.5 µg/m³, 2.3× its usual 20.2 Nong Bua Lamphu, 1 May: 54.2 µg/m³, 2.8× its usual 19.5 Nong Bua Lamphu, 2 May: 55.5 µg/m³, 3.1× its usual 17.9 Nong Bua Lamphu, 3 May: 53.2 µg/m³, 3.1× its usual 17.3 Nong Bua Lamphu, 4 May: 44.9 µg/m³, 2.6× its usual 17.2 Nong Bua Lamphu, 5 May: 39.2 µg/m³, 2.3× its usual 17.2 Nong Bua Lamphu, 6 May: 40.3 µg/m³, 2.4× its usual 17.1 Nong Bua Lamphu, 7 May: 28.3 µg/m³ Nong Bua Lamphu, 8 May: 22.9 µg/m³ Nong Bua Lamphu, 9 May: 28.3 µg/m³ Nong Bua Lamphu, 10 May: 20.6 µg/m³ Vientiane Vientiane, 26 April: 48.9 µg/m³ Vientiane, 27 April: 63.8 µg/m³ Vientiane, 28 April: 60.8 µg/m³ Vientiane, 29 April: 62.3 µg/m³ Vientiane, 30 April: 70.1 µg/m³, 2.0× its usual 34.2 Vientiane, 1 May: 59.2 µg/m³ Vientiane, 2 May: 53.1 µg/m³ Vientiane, 3 May: 43.6 µg/m³ Vientiane, 4 May: 38.6 µg/m³ Vientiane, 5 May: 46.7 µg/m³ Vientiane, 6 May: 29.0 µg/m³ Vientiane, 7 May: 22.8 µg/m³ Vientiane, 8 May: 28.6 µg/m³ Vientiane, 9 May: 17.7 µg/m³ Vientiane, 10 May: 20.2 µg/m³ Loei Loei, 26 April: 40.6 µg/m³ Loei, 27 April: 42.7 µg/m³ Loei, 28 April: 48.4 µg/m³ Loei, 29 April: no reading Loei, 30 April: 54.8 µg/m³, 2.3× its usual 24.3 Loei, 1 May: 64.0 µg/m³, 2.8× its usual 22.7 Loei, 2 May: 60.5 µg/m³, 2.7× its usual 22.5 Loei, 3 May: 57.9 µg/m³, 2.6× its usual 22.2 Loei, 4 May: 47.0 µg/m³, 2.2× its usual 21.6 Loei, 5 May: 43.0 µg/m³, 2.0× its usual 21.5 Loei, 6 May: 45.7 µg/m³, 2.2× its usual 20.5 Loei, 7 May: 31.9 µg/m³ Loei, 8 May: 22.7 µg/m³ Loei, 9 May: 22.5 µg/m³ Loei, 10 May: 14.2 µg/m³ Udon Thani Udon Thani, 26 April: 35.2 µg/m³ Udon Thani, 27 April: 37.5 µg/m³ Udon Thani, 28 April: 43.6 µg/m³ Udon Thani, 29 April: 44.4 µg/m³ Udon Thani, 30 April: 45.2 µg/m³, 2.0× its usual 22.5 Udon Thani, 1 May: 53.5 µg/m³, 2.4× its usual 21.9 Udon Thani, 2 May: 56.2 µg/m³, 2.7× its usual 21.2 Udon Thani, 3 May: 50.6 µg/m³, 2.5× its usual 20.4 Udon Thani, 4 May: 36.8 µg/m³ Udon Thani, 5 May: 41.0 µg/m³, 2.1× its usual 19.6 Udon Thani, 6 May: 36.5 µg/m³ Udon Thani, 7 May: 25.2 µg/m³ Udon Thani, 8 May: 20.1 µg/m³ Udon Thani, 9 May: 27.4 µg/m³ Udon Thani, 10 May: 24.5 µg/m³ Sakon Nakhon Sakon Nakhon, 26 April: 39.5 µg/m³ Sakon Nakhon, 27 April: 37.3 µg/m³ Sakon Nakhon, 28 April: 44.1 µg/m³ Sakon Nakhon, 29 April: 44.5 µg/m³ Sakon Nakhon, 30 April: 43.8 µg/m³, 2.0× its usual 21.7 Sakon Nakhon, 1 May: 49.3 µg/m³, 2.3× its usual 21.7 Sakon Nakhon, 2 May: 54.2 µg/m³, 2.6× its usual 20.6 Sakon Nakhon, 3 May: 51.8 µg/m³, 2.7× its usual 19.0 Sakon Nakhon, 4 May: 40.3 µg/m³, 2.2× its usual 18.2 Sakon Nakhon, 5 May: 41.0 µg/m³, 2.3× its usual 17.7 Sakon Nakhon, 6 May: 28.6 µg/m³ Sakon Nakhon, 7 May: 19.2 µg/m³ Sakon Nakhon, 8 May: 21.4 µg/m³ Sakon Nakhon, 9 May: 23.2 µg/m³ Sakon Nakhon, 10 May: 19.2 µg/m³ Uttaradit Uttaradit, 26 April: 58.8 µg/m³ Uttaradit, 27 April: 53.9 µg/m³ Uttaradit, 28 April: 64.0 µg/m³ Uttaradit, 29 April: 57.0 µg/m³ Uttaradit, 30 April: 56.6 µg/m³ Uttaradit, 1 May: 67.3 µg/m³, 2.2× its usual 31.3 Uttaradit, 2 May: 103.0 µg/m³, 3.7× its usual 27.8 Uttaradit, 3 May: no reading Uttaradit, 4 May: no reading Uttaradit, 5 May: 54.4 µg/m³, 2.0× its usual 26.7 Uttaradit, 6 May: 62.7 µg/m³, 2.4× its usual 26.4 Uttaradit, 7 May: 61.5 µg/m³, 2.3× its usual 26.2 Uttaradit, 8 May: 29.3 µg/m³ Uttaradit, 9 May: 30.4 µg/m³ Uttaradit, 10 May: 27.0 µg/m³ Kalasin Kalasin, 26 April: 45.5 µg/m³ Kalasin, 27 April: 48.5 µg/m³ Kalasin, 28 April: 58.0 µg/m³ Kalasin, 29 April: 50.6 µg/m³ Kalasin, 30 April: 50.3 µg/m³ Kalasin, 1 May: 62.0 µg/m³, 2.0× its usual 30.9 Kalasin, 2 May: 64.3 µg/m³, 2.2× its usual 29.4 Kalasin, 3 May: 70.2 µg/m³, 2.4× its usual 29.3 Kalasin, 4 May: 57.7 µg/m³, 2.0× its usual 28.7 Kalasin, 5 May: 56.2 µg/m³ Kalasin, 6 May: 48.3 µg/m³ Kalasin, 7 May: 33.9 µg/m³ Kalasin, 8 May: 35.8 µg/m³ Kalasin, 9 May: 37.2 µg/m³ Kalasin, 10 May: 24.9 µg/m³ Lamphun Lamphun, 26 April: 59.8 µg/m³ Lamphun, 27 April: 49.6 µg/m³ Lamphun, 28 April: 57.7 µg/m³ Lamphun, 29 April: 57.0 µg/m³ Lamphun, 30 April: 56.2 µg/m³ Lamphun, 1 May: 58.6 µg/m³, 2.1× its usual 28.4 Lamphun, 2 May: 68.8 µg/m³, 2.5× its usual 27.8 Lamphun, 3 May: 55.8 µg/m³, 2.2× its usual 25.2 Lamphun, 4 May: 57.6 µg/m³, 2.4× its usual 23.6 Lamphun, 5 May: 47.6 µg/m³, 2.0× its usual 23.6 Lamphun, 6 May: 55.9 µg/m³, 2.4× its usual 23.5 Lamphun, 7 May: 69.4 µg/m³, 3.0× its usual 23.3 Lamphun, 8 May: 35.6 µg/m³ Lamphun, 9 May: 33.2 µg/m³ Lamphun, 10 May: 22.3 µg/m³ Kamphaeng Phet Kamphaeng Phet, 26 April: 46.8 µg/m³ Kamphaeng Phet, 27 April: 42.3 µg/m³ Kamphaeng Phet, 28 April: 50.8 µg/m³ Kamphaeng Phet, 29 April: 47.6 µg/m³ Kamphaeng Phet, 30 April: 51.2 µg/m³ Kamphaeng Phet, 1 May: 53.4 µg/m³, 2.0× its usual 26.2 Kamphaeng Phet, 2 May: 60.0 µg/m³, 2.5× its usual 23.8 Kamphaeng Phet, 3 May: 43.3 µg/m³ Kamphaeng Phet, 4 May: 41.3 µg/m³ Kamphaeng Phet, 5 May: 37.7 µg/m³ Kamphaeng Phet, 6 May: 52.2 µg/m³, 2.3× its usual 22.4 Kamphaeng Phet, 7 May: 50.4 µg/m³, 2.3× its usual 22.0 Kamphaeng Phet, 8 May: 27.1 µg/m³ Kamphaeng Phet, 9 May: 31.4 µg/m³ Kamphaeng Phet, 10 May: no reading Phetchabun Phetchabun, 26 April: 37.4 µg/m³ Phetchabun, 27 April: 39.6 µg/m³ Phetchabun, 28 April: 40.7 µg/m³ Phetchabun, 29 April: 36.7 µg/m³ Phetchabun, 30 April: 42.4 µg/m³ Phetchabun, 1 May: 49.7 µg/m³, 2.2× its usual 22.5 Phetchabun, 2 May: 54.7 µg/m³, 2.7× its usual 19.9 Phetchabun, 3 May: 54.4 µg/m³, 2.8× its usual 19.6 Phetchabun, 4 May: 51.0 µg/m³, 2.7× its usual 18.8 Phetchabun, 5 May: 43.1 µg/m³, 2.4× its usual 18.3 Phetchabun, 6 May: 47.6 µg/m³, 2.6× its usual 18.2 Phetchabun, 7 May: 42.3 µg/m³, 2.3× its usual 18.1 Phetchabun, 8 May: 26.9 µg/m³ Phetchabun, 9 May: 22.3 µg/m³ Phetchabun, 10 May: 19.2 µg/m³ Ratchaburi Ratchaburi, 26 April: 22.7 µg/m³ Ratchaburi, 27 April: 27.0 µg/m³ Ratchaburi, 28 April: 28.8 µg/m³ Ratchaburi, 29 April: 28.7 µg/m³ Ratchaburi, 30 April: 36.1 µg/m³ Ratchaburi, 1 May: 48.3 µg/m³, 2.1× its usual 22.6 Ratchaburi, 2 May: 48.7 µg/m³, 2.2× its usual 21.8 Ratchaburi, 3 May: 41.4 µg/m³ Ratchaburi, 4 May: 37.5 µg/m³ Ratchaburi, 5 May: 42.3 µg/m³ Ratchaburi, 6 May: 41.3 µg/m³ Ratchaburi, 7 May: no reading Ratchaburi, 8 May: no reading Ratchaburi, 9 May: 27.3 µg/m³ Ratchaburi, 10 May: 21.4 µg/m³ Phetchaburi Phetchaburi, 26 April: 18.2 µg/m³ Phetchaburi, 27 April: 22.9 µg/m³ Phetchaburi, 28 April: 22.4 µg/m³ Phetchaburi, 29 April: 20.5 µg/m³ Phetchaburi, 30 April: 26.3 µg/m³ Phetchaburi, 1 May: 44.5 µg/m³, 2.8× its usual 15.8 Phetchaburi, 2 May: 43.3 µg/m³, 2.8× its usual 15.3 Phetchaburi, 3 May: 36.0 µg/m³, 2.5× its usual 14.2 Phetchaburi, 4 May: 32.3 µg/m³, 2.3× its usual 14.0 Phetchaburi, 5 May: 35.9 µg/m³, 2.7× its usual 13.5 Phetchaburi, 6 May: 35.6 µg/m³, 2.7× its usual 13.0 Phetchaburi, 7 May: 26.7 µg/m³ Phetchaburi, 8 May: 18.7 µg/m³ Phetchaburi, 9 May: 22.4 µg/m³ Phetchaburi, 10 May: 15.4 µg/m³ Nakhon Pathom Nakhon Pathom, 26 April: 16.6 µg/m³ Nakhon Pathom, 27 April: 20.8 µg/m³ Nakhon Pathom, 28 April: 22.8 µg/m³ Nakhon Pathom, 29 April: 27.2 µg/m³ Nakhon Pathom, 30 April: 32.6 µg/m³ Nakhon Pathom, 1 May: 41.7 µg/m³, 2.2× its usual 18.8 Nakhon Pathom, 2 May: 42.0 µg/m³, 2.3× its usual 18.4 Nakhon Pathom, 3 May: 38.5 µg/m³, 2.2× its usual 17.8 Nakhon Pathom, 4 May: 33.2 µg/m³ Nakhon Pathom, 5 May: 35.3 µg/m³, 2.0× its usual 17.5 Nakhon Pathom, 6 May: 34.0 µg/m³ Nakhon Pathom, 7 May: 32.2 µg/m³ Nakhon Pathom, 8 May: 21.1 µg/m³ Nakhon Pathom, 9 May: 20.9 µg/m³ Nakhon Pathom, 10 May: 18.4 µg/m³ Hua Hin Hua Hin, 26 April: 16.7 µg/m³ Hua Hin, 27 April: 23.4 µg/m³ Hua Hin, 28 April: 25.2 µg/m³ Hua Hin, 29 April: 17.1 µg/m³ Hua Hin, 30 April: 24.8 µg/m³ Hua Hin, 1 May: 40.9 µg/m³, 2.5× its usual 16.6 Hua Hin, 2 May: 39.3 µg/m³, 2.4× its usual 16.3 Hua Hin, 3 May: 36.0 µg/m³, 2.2× its usual 16.1 Hua Hin, 4 May: 36.1 µg/m³, 2.3× its usual 16.0 Hua Hin, 5 May: 33.9 µg/m³, 2.1× its usual 15.9 Hua Hin, 6 May: 40.2 µg/m³, 2.6× its usual 15.2 Hua Hin, 7 May: 31.4 µg/m³ Hua Hin, 8 May: 17.9 µg/m³ Hua Hin, 9 May: 22.4 µg/m³ Hua Hin, 10 May: 13.1 µg/m³ Ranong Ranong, 26 April: 23.2 µg/m³ Ranong, 27 April: 22.7 µg/m³ Ranong, 28 April: 20.3 µg/m³ Ranong, 29 April: 18.7 µg/m³ Ranong, 30 April: 20.5 µg/m³ Ranong, 1 May: 30.0 µg/m³, 3.0× its usual 9.9 Ranong, 2 May: 32.5 µg/m³, 3.4× its usual 9.6 Ranong, 3 May: 30.7 µg/m³, 3.3× its usual 9.4 Ranong, 4 May: 26.0 µg/m³, 2.8× its usual 9.4 Ranong, 5 May: 26.8 µg/m³, 2.9× its usual 9.1 Ranong, 6 May: 25.2 µg/m³, 2.8× its usual 9.0 Ranong, 7 May: 19.5 µg/m³ Ranong, 8 May: 11.2 µg/m³ Ranong, 9 May: 10.4 µg/m³ Ranong, 10 May: 8.5 µg/m³ Ubon Ratchathani Ubon Ratchathani, 26 April: 82.2 µg/m³ Ubon Ratchathani, 27 April: 78.7 µg/m³ Ubon Ratchathani, 28 April: 68.5 µg/m³ Ubon Ratchathani, 29 April: 79.5 µg/m³ Ubon Ratchathani, 30 April: 91.3 µg/m³ Ubon Ratchathani, 1 May: 75.9 µg/m³ Ubon Ratchathani, 2 May: 110.0 µg/m³, 2.6× its usual 43.1 Ubon Ratchathani, 3 May: 112.0 µg/m³, 2.7× its usual 41.8 Ubon Ratchathani, 4 May: 71.1 µg/m³ Ubon Ratchathani, 5 May: 54.7 µg/m³ Ubon Ratchathani, 6 May: no reading Ubon Ratchathani, 7 May: no reading Ubon Ratchathani, 8 May: 33.8 µg/m³ Ubon Ratchathani, 9 May: 47.2 µg/m³ Ubon Ratchathani, 10 May: 66.7 µg/m³ Phrae Phrae, 26 April: 48.8 µg/m³ Phrae, 27 April: 50.4 µg/m³ Phrae, 28 April: 56.3 µg/m³ Phrae, 29 April: 48.4 µg/m³ Phrae, 30 April: 49.4 µg/m³ Phrae, 1 May: 55.9 µg/m³ Phrae, 2 May: 80.5 µg/m³, 2.9× its usual 28.0 Phrae, 3 May: 74.9 µg/m³, 2.8× its usual 26.4 Phrae, 4 May: 49.5 µg/m³ Phrae, 5 May: 55.1 µg/m³, 2.2× its usual 25.5 Phrae, 6 May: 58.9 µg/m³, 2.4× its usual 24.9 Phrae, 7 May: 53.4 µg/m³, 2.2× its usual 23.9 Phrae, 8 May: 28.2 µg/m³ Phrae, 9 May: 31.8 µg/m³ Phrae, 10 May: 28.3 µg/m³ Sukhothai Sukhothai, 26 April: 47.8 µg/m³ Sukhothai, 27 April: 40.5 µg/m³ Sukhothai, 28 April: 52.1 µg/m³ Sukhothai, 29 April: 49.0 µg/m³ Sukhothai, 30 April: 48.2 µg/m³ Sukhothai, 1 May: 52.5 µg/m³ Sukhothai, 2 May: 69.9 µg/m³, 2.4× its usual 29.3 Sukhothai, 3 May: 60.1 µg/m³, 2.2× its usual 27.6 Sukhothai, 4 May: 47.8 µg/m³ Sukhothai, 5 May: 51.6 µg/m³, 2.0× its usual 25.3 Sukhothai, 6 May: 67.0 µg/m³, 2.7× its usual 24.9 Sukhothai, 7 May: 60.5 µg/m³, 2.5× its usual 24.2 Sukhothai, 8 May: 39.0 µg/m³ Sukhothai, 9 May: 36.4 µg/m³ Sukhothai, 10 May: 25.2 µg/m³ Mukdahan Mukdahan, 26 April: 59.6 µg/m³ Mukdahan, 27 April: 53.3 µg/m³ Mukdahan, 28 April: 51.5 µg/m³ Mukdahan, 29 April: 52.7 µg/m³ Mukdahan, 30 April: 50.2 µg/m³ Mukdahan, 1 May: 49.7 µg/m³ Mukdahan, 2 May: 66.9 µg/m³, 2.1× its usual 32.3 Mukdahan, 3 May: 62.9 µg/m³, 2.2× its usual 28.7 Mukdahan, 4 May: 52.6 µg/m³ Mukdahan, 5 May: 51.9 µg/m³ Mukdahan, 6 May: 47.6 µg/m³ Mukdahan, 7 May: 37.6 µg/m³ Mukdahan, 8 May: 34.8 µg/m³ Mukdahan, 9 May: 36.7 µg/m³ Mukdahan, 10 May: 36.8 µg/m³ Phichit Phichit, 26 April: 33.7 µg/m³ Phichit, 27 April: 34.0 µg/m³ Phichit, 28 April: 39.8 µg/m³ Phichit, 29 April: 31.6 µg/m³ Phichit, 30 April: 31.3 µg/m³ Phichit, 1 May: 49.0 µg/m³ Phichit, 2 May: 54.4 µg/m³, 2.1× its usual 25.7 Phichit, 3 May: 54.6 µg/m³, 2.3× its usual 24.0 Phichit, 4 May: 43.2 µg/m³ Phichit, 5 May: 41.1 µg/m³ Phichit, 6 May: 44.4 µg/m³, 2.0× its usual 21.7 Phichit, 7 May: 37.9 µg/m³ Phichit, 8 May: 25.5 µg/m³ Phichit, 9 May: 21.3 µg/m³ Phichit, 10 May: 21.2 µg/m³ Nakhon Sawan Nakhon Sawan, 26 April: 27.0 µg/m³ Nakhon Sawan, 27 April: 27.3 µg/m³ Nakhon Sawan, 28 April: 30.8 µg/m³ Nakhon Sawan, 29 April: 31.6 µg/m³ Nakhon Sawan, 30 April: 31.5 µg/m³ Nakhon Sawan, 1 May: 44.2 µg/m³ Nakhon Sawan, 2 May: 53.2 µg/m³, 2.0× its usual 26.5 Nakhon Sawan, 3 May: 51.2 µg/m³ Nakhon Sawan, 4 May: 43.2 µg/m³ Nakhon Sawan, 5 May: 38.6 µg/m³ Nakhon Sawan, 6 May: 43.6 µg/m³ Nakhon Sawan, 7 May: 40.7 µg/m³ Nakhon Sawan, 8 May: 29.7 µg/m³ Nakhon Sawan, 9 May: 25.5 µg/m³ Nakhon Sawan, 10 May: 26.2 µg/m³ Chaiyaphum Chaiyaphum, 26 April: 28.7 µg/m³ Chaiyaphum, 27 April: 26.1 µg/m³ Chaiyaphum, 28 April: 36.4 µg/m³ Chaiyaphum, 29 April: 30.8 µg/m³ Chaiyaphum, 30 April: 28.2 µg/m³ Chaiyaphum, 1 May: 43.4 µg/m³ Chaiyaphum, 2 May: 47.8 µg/m³, 2.1× its usual 22.9 Chaiyaphum, 3 May: 40.0 µg/m³ Chaiyaphum, 4 May: 35.9 µg/m³ Chaiyaphum, 5 May: 25.6 µg/m³ Chaiyaphum, 6 May: 32.9 µg/m³ Chaiyaphum, 7 May: 23.8 µg/m³ Chaiyaphum, 8 May: 16.9 µg/m³ Chaiyaphum, 9 May: 17.2 µg/m³ Chaiyaphum, 10 May: 18.7 µg/m³ Bangkok Bangkok, 26 April: 14.9 µg/m³ Bangkok, 27 April: 18.6 µg/m³ Bangkok, 28 April: 18.0 µg/m³ Bangkok, 29 April: 14.0 µg/m³ Bangkok, 30 April: 21.5 µg/m³ Bangkok, 1 May: 37.9 µg/m³ Bangkok, 2 May: 41.6 µg/m³, 2.0× its usual 20.8 Bangkok, 3 May: 36.2 µg/m³ Bangkok, 4 May: 29.4 µg/m³ Bangkok, 5 May: 36.5 µg/m³ Bangkok, 6 May: 38.3 µg/m³ Bangkok, 7 May: 27.8 µg/m³ Bangkok, 8 May: 21.9 µg/m³ Bangkok, 9 May: 21.4 µg/m³ Bangkok, 10 May: 19.4 µg/m³ Ban Samae Dam Ban Samae Dam, 26 April: 15.2 µg/m³ Ban Samae Dam, 27 April: 19.2 µg/m³ Ban Samae Dam, 28 April: 18.5 µg/m³ Ban Samae Dam, 29 April: 14.4 µg/m³ Ban Samae Dam, 30 April: 23.8 µg/m³ Ban Samae Dam, 1 May: 38.7 µg/m³ Ban Samae Dam, 2 May: 41.6 µg/m³, 2.0× its usual 20.7 Ban Samae Dam, 3 May: 36.3 µg/m³ Ban Samae Dam, 4 May: 32.8 µg/m³ Ban Samae Dam, 5 May: 38.5 µg/m³, 2.0× its usual 19.2 Ban Samae Dam, 6 May: 38.8 µg/m³, 2.1× its usual 18.8 Ban Samae Dam, 7 May: 31.8 µg/m³ Ban Samae Dam, 8 May: 27.3 µg/m³ Ban Samae Dam, 9 May: 22.1 µg/m³ Ban Samae Dam, 10 May: 19.8 µg/m³ Mueang Nonthaburi Mueang Nonthaburi, 26 April: 13.6 µg/m³ Mueang Nonthaburi, 27 April: 17.4 µg/m³ Mueang Nonthaburi, 28 April: 17.9 µg/m³ Mueang Nonthaburi, 29 April: 13.7 µg/m³ Mueang Nonthaburi, 30 April: 21.6 µg/m³ Mueang Nonthaburi, 1 May: 35.9 µg/m³ Mueang Nonthaburi, 2 May: 39.4 µg/m³, 2.1× its usual 18.4 Mueang Nonthaburi, 3 May: 33.5 µg/m³ Mueang Nonthaburi, 4 May: 29.3 µg/m³ Mueang Nonthaburi, 5 May: 33.6 µg/m³ Mueang Nonthaburi, 6 May: 36.3 µg/m³, 2.1× its usual 16.9 Mueang Nonthaburi, 7 May: 27.6 µg/m³ Mueang Nonthaburi, 8 May: 20.4 µg/m³ Mueang Nonthaburi, 9 May: 21.3 µg/m³ Mueang Nonthaburi, 10 May: 18.7 µg/m³ Nakhon Nayok Nakhon Nayok, 26 April: 18.7 µg/m³ Nakhon Nayok, 27 April: 18.1 µg/m³ Nakhon Nayok, 28 April: 20.5 µg/m³ Nakhon Nayok, 29 April: 20.1 µg/m³ Nakhon Nayok, 30 April: 22.9 µg/m³ Nakhon Nayok, 1 May: 26.9 µg/m³ Nakhon Nayok, 2 May: 38.1 µg/m³, 2.3× its usual 16.7 Nakhon Nayok, 3 May: 33.8 µg/m³, 2.2× its usual 15.3 Nakhon Nayok, 4 May: 29.5 µg/m³ Nakhon Nayok, 5 May: 31.2 µg/m³, 2.1× its usual 14.8 Nakhon Nayok, 6 May: 33.0 µg/m³, 2.3× its usual 14.5 Nakhon Nayok, 7 May: 25.5 µg/m³ Nakhon Nayok, 8 May: 18.2 µg/m³ Nakhon Nayok, 9 May: 20.5 µg/m³ Nakhon Nayok, 10 May: 19.8 µg/m³ Phuket Phuket, 26 April: 25.9 µg/m³ Phuket, 27 April: 23.4 µg/m³ Phuket, 28 April: 25.3 µg/m³ Phuket, 29 April: 24.5 µg/m³ Phuket, 30 April: 22.0 µg/m³ Phuket, 1 May: 30.4 µg/m³ Phuket, 2 May: 37.9 µg/m³, 2.5× its usual 15.3 Phuket, 3 May: 37.8 µg/m³, 2.5× its usual 15.0 Phuket, 4 May: 35.9 µg/m³, 2.4× its usual 14.8 Phuket, 5 May: 33.7 µg/m³, 2.2× its usual 15.0 Phuket, 6 May: no reading Phuket, 7 May: 24.4 µg/m³ Phuket, 8 May: 16.2 µg/m³ Phuket, 9 May: 17.6 µg/m³ Phuket, 10 May: 14.4 µg/m³ Si Sa Ket Si Sa Ket, 26 April: 34.4 µg/m³ Si Sa Ket, 27 April: 26.2 µg/m³ Si Sa Ket, 28 April: 20.1 µg/m³ Si Sa Ket, 29 April: 33.7 µg/m³ Si Sa Ket, 30 April: 41.2 µg/m³ Si Sa Ket, 1 May: 27.5 µg/m³ Si Sa Ket, 2 May: 49.2 µg/m³ Si Sa Ket, 3 May: 66.1 µg/m³, 2.6× its usual 25.9 Si Sa Ket, 4 May: no reading Si Sa Ket, 5 May: 34.0 µg/m³ Si Sa Ket, 6 May: 32.4 µg/m³ Si Sa Ket, 7 May: 17.8 µg/m³ Si Sa Ket, 8 May: no reading Si Sa Ket, 9 May: 40.3 µg/m³ Si Sa Ket, 10 May: no reading Amnat Charoen Amnat Charoen, 26 April: no reading Amnat Charoen, 27 April: no reading Amnat Charoen, 28 April: 37.1 µg/m³ Amnat Charoen, 29 April: 39.9 µg/m³ Amnat Charoen, 30 April: 45.2 µg/m³ Amnat Charoen, 1 May: 41.1 µg/m³ Amnat Charoen, 2 May: 59.2 µg/m³ Amnat Charoen, 3 May: 61.2 µg/m³, 2.1× its usual 29.4 Amnat Charoen, 4 May: 47.4 µg/m³ Amnat Charoen, 5 May: 42.8 µg/m³ Amnat Charoen, 6 May: 36.2 µg/m³ Amnat Charoen, 7 May: 20.5 µg/m³ Amnat Charoen, 8 May: 25.7 µg/m³ Amnat Charoen, 9 May: 35.5 µg/m³ Amnat Charoen, 10 May: 34.1 µg/m³ Pattani Pattani, 26 April: 16.2 µg/m³ Pattani, 27 April: 16.8 µg/m³ Pattani, 28 April: 18.4 µg/m³ Pattani, 29 April: 18.1 µg/m³ Pattani, 30 April: 19.8 µg/m³ Pattani, 1 May: 22.3 µg/m³ Pattani, 2 May: 18.9 µg/m³ Pattani, 3 May: 28.6 µg/m³, 2.8× its usual 10.4 Pattani, 4 May: 18.1 µg/m³ Pattani, 5 May: 21.6 µg/m³ Pattani, 6 May: 21.4 µg/m³ Pattani, 7 May: 18.2 µg/m³ Pattani, 8 May: 15.4 µg/m³ Pattani, 9 May: 18.5 µg/m³ Pattani, 10 May: 11.9 µg/m³ Surin Surin, 26 April: 26.6 µg/m³ Surin, 27 April: 18.7 µg/m³ Surin, 28 April: 14.1 µg/m³ Surin, 29 April: 16.4 µg/m³ Surin, 30 April: 19.2 µg/m³ Surin, 1 May: 19.2 µg/m³ Surin, 2 May: 26.3 µg/m³ Surin, 3 May: 32.2 µg/m³ Surin, 4 May: 34.8 µg/m³, 2.0× its usual 17.3 Surin, 5 May: 24.7 µg/m³ Surin, 6 May: 28.8 µg/m³ Surin, 7 May: no reading Surin, 8 May: no reading Surin, 9 May: 26.9 µg/m³ Surin, 10 May: 26.6 µg/m³ Roi Et Roi Et, 26 April: 29.7 µg/m³ Roi Et, 27 April: 27.5 µg/m³ Roi Et, 28 April: 32.5 µg/m³ Roi Et, 29 April: 30.5 µg/m³ Roi Et, 30 April: 31.3 µg/m³ Roi Et, 1 May: 36.3 µg/m³ Roi Et, 2 May: 46.1 µg/m³ Roi Et, 3 May: 44.4 µg/m³ Roi Et, 4 May: 53.0 µg/m³ Roi Et, 5 May: 55.2 µg/m³, 2.0× its usual 27.5 Roi Et, 6 May: 44.5 µg/m³ Roi Et, 7 May: 27.6 µg/m³ Roi Et, 8 May: 33.2 µg/m³ Roi Et, 9 May: 33.9 µg/m³ Roi Et, 10 May: 24.7 µg/m³ Samut Prakan Samut Prakan, 26 April: 11.1 µg/m³ Samut Prakan, 27 April: 14.1 µg/m³ Samut Prakan, 28 April: 14.7 µg/m³ Samut Prakan, 29 April: 10.1 µg/m³ Samut Prakan, 30 April: 15.0 µg/m³ Samut Prakan, 1 May: 31.9 µg/m³ Samut Prakan, 2 May: no reading Samut Prakan, 3 May: no reading Samut Prakan, 4 May: no reading Samut Prakan, 5 May: 33.1 µg/m³, 2.2× its usual 14.9 Samut Prakan, 6 May: 37.8 µg/m³, 2.6× its usual 14.7 Samut Prakan, 7 May: 28.1 µg/m³ Samut Prakan, 8 May: 20.5 µg/m³ Samut Prakan, 9 May: 17.7 µg/m³ Samut Prakan, 10 May: 13.5 µg/m³ Nong Khaem Nong Khaem, 26 April: 16.0 µg/m³ Nong Khaem, 27 April: 19.7 µg/m³ Nong Khaem, 28 April: 21.8 µg/m³ Nong Khaem, 29 April: 16.0 µg/m³ Nong Khaem, 30 April: 26.6 µg/m³ Nong Khaem, 1 May: 38.4 µg/m³ Nong Khaem, 2 May: 43.1 µg/m³ Nong Khaem, 3 May: 37.4 µg/m³ Nong Khaem, 4 May: 35.2 µg/m³ Nong Khaem, 5 May: 40.3 µg/m³ Nong Khaem, 6 May: 40.3 µg/m³, 2.0× its usual 19.7 Nong Khaem, 7 May: 33.3 µg/m³ Nong Khaem, 8 May: 25.9 µg/m³ Nong Khaem, 9 May: 28.6 µg/m³ Nong Khaem, 10 May: 22.1 µg/m³ Phra Nakhon Si Ayut… Phra Nakhon Si Ayutthaya, 26 April: 18.9 µg/m³ Phra Nakhon Si Ayutthaya, 27 April: 18.4 µg/m³ Phra Nakhon Si Ayutthaya, 28 April: 19.2 µg/m³ Phra Nakhon Si Ayutthaya, 29 April: 14.9 µg/m³ Phra Nakhon Si Ayutthaya, 30 April: 21.0 µg/m³ Phra Nakhon Si Ayutthaya, 1 May: 33.4 µg/m³ Phra Nakhon Si Ayutthaya, 2 May: 39.0 µg/m³ Phra Nakhon Si Ayutthaya, 3 May: 39.0 µg/m³ Phra Nakhon Si Ayutthaya, 4 May: 33.4 µg/m³ Phra Nakhon Si Ayutthaya, 5 May: 34.8 µg/m³ Phra Nakhon Si Ayutthaya, 6 May: 39.2 µg/m³, 2.1× its usual 18.9 Phra Nakhon Si Ayutthaya, 7 May: 29.8 µg/m³ Phra Nakhon Si Ayutthaya, 8 May: 16.2 µg/m³ Phra Nakhon Si Ayutthaya, 9 May: 24.5 µg/m³ Phra Nakhon Si Ayutthaya, 10 May: 18.6 µg/m³ Ban Khlong Prawet Ban Khlong Prawet, 26 April: 11.8 µg/m³ Ban Khlong Prawet, 27 April: 14.1 µg/m³ Ban Khlong Prawet, 28 April: 11.4 µg/m³ Ban Khlong Prawet, 29 April: 9.4 µg/m³ Ban Khlong Prawet, 30 April: 19.7 µg/m³ Ban Khlong Prawet, 1 May: 32.6 µg/m³ Ban Khlong Prawet, 2 May: 34.2 µg/m³ Ban Khlong Prawet, 3 May: 27.3 µg/m³ Ban Khlong Prawet, 4 May: 26.1 µg/m³ Ban Khlong Prawet, 5 May: 33.7 µg/m³ Ban Khlong Prawet, 6 May: 33.2 µg/m³, 2.0× its usual 16.4 Ban Khlong Prawet, 7 May: 19.3 µg/m³ Ban Khlong Prawet, 8 May: 20.4 µg/m³ Ban Khlong Prawet, 9 May: 22.7 µg/m³ Ban Khlong Prawet, 10 May: 14.8 µg/m³ Laem Chabang Laem Chabang, 26 April: 9.5 µg/m³ Laem Chabang, 27 April: 10.9 µg/m³ Laem Chabang, 28 April: 8.9 µg/m³ Laem Chabang, 29 April: 6.1 µg/m³ Laem Chabang, 30 April: 10.5 µg/m³ Laem Chabang, 1 May: 19.8 µg/m³ Laem Chabang, 2 May: 32.1 µg/m³ Laem Chabang, 3 May: 25.7 µg/m³ Laem Chabang, 4 May: 20.5 µg/m³ Laem Chabang, 5 May: 26.0 µg/m³ Laem Chabang, 6 May: 33.1 µg/m³, 2.2× its usual 15.2 Laem Chabang, 7 May: 23.0 µg/m³ Laem Chabang, 8 May: 13.5 µg/m³ Laem Chabang, 9 May: 16.3 µg/m³ Laem Chabang, 10 May: 14.9 µg/m³ 26 Apr 28 30 1 May 2 4 6 8 10 Every counted city, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Chiang Rai Chiang Rai, Thailand 9 5 May 21.4 7.2× Ban Houakhoua Bokeo, Laos 9 2 May 33.7 7.0× Mae Sai Chiang Rai, Thailand 9 2 May 31.2 3.9× Uttaradit Uttaradit, Thailand 5 2 May 27.8 3.7× Phayao Phayao, Thailand 9 2 May 30.1 3.5× Ranong Ranong province, Thailand 6 2 May 9.6 3.4× Chiang Mai Chiang Mai, Thailand 9 2 May 25.3 3.2× Pakxan Bolikhamsai, Laos 6 1 May 24.0 3.1× Nong Bua Lamphu Nong Bua Lamphu, Thailand 8 2 May 17.9 3.1× Lamphun Lamphun, Thailand 7 7 May 23.3 3.0× Phrae Phrae, Thailand 5 2 May 28.0 2.9× Lampang Lampang, Thailand 5 2 May 34.2 2.8× Loei Loei, Thailand 7 1 May 22.7 2.8× Phetchaburi Phetchaburi, Thailand 6 1 May 15.8 2.8× Pattani Pattani, Thailand 1 3 May 10.4 2.8× Ubon Ratchathani Ubon Ratchathani, Thailand 2 3 May 41.8 2.7× Udon Thani Udon Thani, Thailand 5 2 May 21.2 2.7× Phetchabun Phetchabun, Thailand 7 2 May 19.9 2.7× Si Sa Ket Si Sa Ket, Thailand 1 3 May 25.9 2.6× Sakon Nakhon Sakon Nakhon, Thailand 6 2 May 20.6 2.6× Samut Prakan Samut Prakan, Thailand 2 6 May 14.7 2.6× Kamphaeng Phet Kamphaeng Phet, Thailand 4 2 May 23.8 2.5× Hua Hin Prachuap Khiri Khan, Thailand 6 1 May 16.6 2.5× Phuket Phuket, Thailand 4 2 May 15.3 2.5× Kalasin Kalasin, Thailand 4 3 May 29.3 2.4× Sukhothai Sukhothai, Thailand 5 2 May 29.3 2.4× Nan Nan, Thailand 4 2 May 38.5 2.3× Phichit Phichit, Thailand 3 3 May 24.0 2.3× Nakhon Pathom Nakhon Pathom, Thailand 4 2 May 18.4 2.3× Nakhon Nayok Nakhon Nayok, Thailand 4 2 May 16.7 2.3× Ratchaburi Ratchaburi, Thailand 2 2 May 21.8 2.2× Laem Chabang Chon Buri, Thailand 1 6 May 15.2 2.2× Mukdahan Mukdahan, Thailand 2 2 May 32.3 2.1× Amnat Charoen Amnat Charoen, Thailand 1 3 May 29.4 2.1× Chaiyaphum Chaiyaphum, Thailand 1 2 May 22.9 2.1× Mueang Nonthaburi Nonthaburi, Thailand 2 2 May 18.4 2.1× Phra Nakhon Si Ayutthaya Phra Nakhon Si Ayutthaya, Thailand 1 6 May 18.9 2.1× Vientiane Vientiane Prefecture, Laos 1 30 April 34.2 2.0× Roi Et Roi Et, Thailand 1 5 May 27.5 2.0× Nakhon Sawan Nakhon Sawan, Thailand 1 2 May 26.5 2.0× Bangkok Bangkok, Thailand 1 2 May 20.8 2.0× Ban Samae Dam Bangkok, Thailand 3 2 May 20.7 2.0× Nong Khaem Bangkok, Thailand 1 6 May 19.7 2.0× Surin Surin, Thailand 1 4 May 17.3 2.0× Ban Khlong Prawet Bangkok, Thailand 1 6 May 16.4 2.0×
Daily means in µg/m³, over the days each city counted in this episode. Highest: its highest of those days. Usual: the city's median for the time of year of that day (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that, with a usual under 5 µg/m³ taken as 5.
Against other episodes in Thailand and Laos
Number 4 of 23 episodes in Thailand and Laos since our records began, by cities reached.
Thailand and Laos, March 2025 53 Thailand, February 2024 51 Thailand, January 2025 50 Thailand and Laos, April and May 2024 45 Northern Thailand and Laos, 20 to 22 May 2023 41 Thailand, April 2023 35 Thailand and Laos, January and February 2023 34 Northern Thailand and Laos, 16 to 18 May 2023 30 Northern Thailand and Laos, October 2024 24 Thailand and Laos, November and December 2025 22 Thailand, February 2025 17 Northern Thailand, May 2023 17 Bars: cities reached; colour: the level of the episode's highest daily reading. All 23 .
Use this page SmogRank, Thailand and Laos, April and May 2024: 45 cities with PM2.5 at twice their usual or more, 29 April to 7 May 2024, smogrank.com/episodes/2024-04-thailand-and-laos (accessed 4 October 2026).
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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms .
An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes . Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.
