SmogRank / Episodes / Thailand
Northern Thailand and Laos, October 2024
For 1 day, on 6 October 2024, 24 cities in Thailand and Laos had PM2.5 at least twice their usual for the time of year. The worst reading was Kanchanaburi, Kanchanaburi, Thailand: 45.4 µg/m³ on 6 October, about 3.6× its usual 12.5.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 24 in 2 countries
Days 1 6 October 2024
Worst day 6 October 24 cities counted
Furthest above usual 4.9× Ubon Ratchathani
Day by day
Play 6 October 24 cities at twice their usual or more
Phetchabun Nong Bua Lamphu Phichit Saraburi Nakhon Sawan Nakhon Nayok Si Maha Phot Si Sa Ket Phra Nakhon Si Ayutthaya Aranyaprathet Sukhothai Nong Chok Pakxan Suphan Buri Kamphaeng Phet Khlong Sam Wa Sai Mai Khan Na Yao Lak Si Lat Krabang Bueng Kum Saphan Sung Bang Kapi Phrae Ban Khlong Prawet Bang Bo District Bang Na Bangkok Phra Pradaeng Samut Prakan Lampang Mae Sot Phayao Lamphun Chiang Mai Khlong Luang Ban Samae Dam Tha Bo Mueang Nonthaburi Sing Buri Vientiane Samut Sakhon Amnat Charoen Nakhon Ratchasima Kalasin Nong Khaem Nan Udon Thani Ratchaburi Nakhon Pathom Yasothon Chaiyaphum Mukdahan Lop Buri Kanchanaburi Surin Sakon Nakhon Buri Ram Ubon Ratchathani 3 Oct 4 5 6 7 8 9 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
Kanchanaburi Kanchanaburi, 3 October: no reading Kanchanaburi, 4 October: no reading Kanchanaburi, 5 October: no reading Kanchanaburi, 6 October: 45.4 µg/m³, 3.6× its usual 12.5 Kanchanaburi, 7 October: no reading Kanchanaburi, 8 October: no reading Kanchanaburi, 9 October: no reading Nong Khaem Nong Khaem, 3 October: 10.9 µg/m³ Nong Khaem, 4 October: 14.2 µg/m³ Nong Khaem, 5 October: 20.7 µg/m³ Nong Khaem, 6 October: 43.1 µg/m³, 2.4× its usual 17.6 Nong Khaem, 7 October: 28.2 µg/m³ Nong Khaem, 8 October: 39.9 µg/m³ Nong Khaem, 9 October: 24.1 µg/m³ Samut Sakhon Samut Sakhon, 3 October: 13.5 µg/m³ Samut Sakhon, 4 October: no reading Samut Sakhon, 5 October: 39.0 µg/m³ Samut Sakhon, 6 October: 41.0 µg/m³, 2.3× its usual 17.5 Samut Sakhon, 7 October: 35.5 µg/m³ Samut Sakhon, 8 October: 50.6 µg/m³ Samut Sakhon, 9 October: 38.7 µg/m³ Vientiane Vientiane, 3 October: 12.0 µg/m³ Vientiane, 4 October: 17.4 µg/m³ Vientiane, 5 October: 31.5 µg/m³ Vientiane, 6 October: 37.8 µg/m³, 2.3× its usual 16.4 Vientiane, 7 October: 44.0 µg/m³ Vientiane, 8 October: 35.7 µg/m³ Vientiane, 9 October: 42.9 µg/m³ Tha Bo Tha Bo, 3 October: 12.0 µg/m³ Tha Bo, 4 October: 17.4 µg/m³ Tha Bo, 5 October: 31.5 µg/m³ Tha Bo, 6 October: 37.8 µg/m³, 2.1× its usual 17.8 Tha Bo, 7 October: 44.0 µg/m³ Tha Bo, 8 October: 35.7 µg/m³ Tha Bo, 9 October: 42.9 µg/m³ Sing Buri Sing Buri, 3 October: no reading Sing Buri, 4 October: no reading Sing Buri, 5 October: no reading Sing Buri, 6 October: 36.2 µg/m³, 2.2× its usual 16.1 Sing Buri, 7 October: no reading Sing Buri, 8 October: no reading Sing Buri, 9 October: no reading Ban Samae Dam Ban Samae Dam, 3 October: 14.5 µg/m³ Ban Samae Dam, 4 October: 15.1 µg/m³ Ban Samae Dam, 5 October: 24.4 µg/m³ Ban Samae Dam, 6 October: 36.1 µg/m³, 2.1× its usual 16.8 Ban Samae Dam, 7 October: 30.1 µg/m³ Ban Samae Dam, 8 October: 41.0 µg/m³ Ban Samae Dam, 9 October: 27.9 µg/m³ Nakhon Pathom Nakhon Pathom, 3 October: 9.8 µg/m³ Nakhon Pathom, 4 October: no reading Nakhon Pathom, 5 October: 27.0 µg/m³ Nakhon Pathom, 6 October: 36.0 µg/m³, 2.7× its usual 13.1 Nakhon Pathom, 7 October: 27.2 µg/m³ Nakhon Pathom, 8 October: 41.5 µg/m³ Nakhon Pathom, 9 October: 28.8 µg/m³ Mukdahan Mukdahan, 3 October: no reading Mukdahan, 4 October: no reading Mukdahan, 5 October: no reading Mukdahan, 6 October: 34.9 µg/m³, 3.3× its usual 10.7 Mukdahan, 7 October: no reading Mukdahan, 8 October: no reading Mukdahan, 9 October: no reading Kalasin Kalasin, 3 October: no reading Kalasin, 4 October: no reading Kalasin, 5 October: no reading Kalasin, 6 October: 34.3 µg/m³, 2.4× its usual 14.2 Kalasin, 7 October: no reading Kalasin, 8 October: no reading Kalasin, 9 October: no reading Ubon Ratchathani Ubon Ratchathani, 3 October: no reading Ubon Ratchathani, 4 October: no reading Ubon Ratchathani, 5 October: no reading Ubon Ratchathani, 6 October: 34.0 µg/m³, 4.9× its usual 7.0 Ubon Ratchathani, 7 October: no reading Ubon Ratchathani, 8 October: no reading Ubon Ratchathani, 9 October: no reading Yasothon Yasothon, 3 October: no reading Yasothon, 4 October: no reading Yasothon, 5 October: no reading Yasothon, 6 October: 31.5 µg/m³, 2.9× its usual 10.9 Yasothon, 7 October: no reading Yasothon, 8 October: no reading Yasothon, 9 October: no reading Khlong Luang Khlong Luang, 3 October: 15.0 µg/m³ Khlong Luang, 4 October: no reading Khlong Luang, 5 October: 18.3 µg/m³ Khlong Luang, 6 October: 31.2 µg/m³, 2.0× its usual 15.5 Khlong Luang, 7 October: 26.5 µg/m³ Khlong Luang, 8 October: 27.2 µg/m³ Khlong Luang, 9 October: 19.9 µg/m³ Nakhon Ratchasima Nakhon Ratchasima, 3 October: no reading Nakhon Ratchasima, 4 October: no reading Nakhon Ratchasima, 5 October: no reading Nakhon Ratchasima, 6 October: 29.7 µg/m³, 2.4× its usual 12.5 Nakhon Ratchasima, 7 October: no reading Nakhon Ratchasima, 8 October: no reading Nakhon Ratchasima, 9 October: no reading Amnat Charoen Amnat Charoen, 3 October: no reading Amnat Charoen, 4 October: no reading Amnat Charoen, 5 October: no reading Amnat Charoen, 6 October: 29.7 µg/m³, 2.4× its usual 12.3 Amnat Charoen, 7 October: no reading Amnat Charoen, 8 October: no reading Amnat Charoen, 9 October: no reading Sakon Nakhon Sakon Nakhon, 3 October: no reading Sakon Nakhon, 4 October: no reading Sakon Nakhon, 5 October: no reading Sakon Nakhon, 6 October: 28.9 µg/m³, 4.0× its usual 7.3 Sakon Nakhon, 7 October: no reading Sakon Nakhon, 8 October: no reading Sakon Nakhon, 9 October: no reading Ratchaburi Ratchaburi, 3 October: no reading Ratchaburi, 4 October: no reading Ratchaburi, 5 October: no reading Ratchaburi, 6 October: 28.6 µg/m³, 2.6× its usual 10.9 Ratchaburi, 7 October: no reading Ratchaburi, 8 October: no reading Ratchaburi, 9 October: no reading Lop Buri Lop Buri, 3 October: no reading Lop Buri, 4 October: no reading Lop Buri, 5 October: no reading Lop Buri, 6 October: 28.5 µg/m³, 3.4× its usual 8.4 Lop Buri, 7 October: no reading Lop Buri, 8 October: no reading Lop Buri, 9 October: no reading Nan Nan, 3 October: no reading Nan, 4 October: no reading Nan, 5 October: no reading Nan, 6 October: 28.5 µg/m³, 2.5× its usual 11.5 Nan, 7 October: no reading Nan, 8 October: no reading Nan, 9 October: no reading Buri Ram Buri Ram, 3 October: no reading Buri Ram, 4 October: no reading Buri Ram, 5 October: no reading Buri Ram, 6 October: 27.2 µg/m³, 4.4× its usual 6.2 Buri Ram, 7 October: no reading Buri Ram, 8 October: no reading Buri Ram, 9 October: no reading Udon Thani Udon Thani, 3 October: no reading Udon Thani, 4 October: no reading Udon Thani, 5 October: no reading Udon Thani, 6 October: 26.6 µg/m³, 2.6× its usual 10.1 Udon Thani, 7 October: no reading Udon Thani, 8 October: no reading Udon Thani, 9 October: no reading Surin Surin, 3 October: no reading Surin, 4 October: no reading Surin, 5 October: no reading Surin, 6 October: 26.2 µg/m³, 4.0× its usual 6.6 Surin, 7 October: no reading Surin, 8 October: no reading Surin, 9 October: no reading Mueang Nonthaburi Mueang Nonthaburi, 3 October: 8.8 µg/m³ Mueang Nonthaburi, 4 October: 6.3 µg/m³ Mueang Nonthaburi, 5 October: 15.6 µg/m³ Mueang Nonthaburi, 6 October: 26.2 µg/m³, 2.2× its usual 11.8 Mueang Nonthaburi, 7 October: 26.4 µg/m³ Mueang Nonthaburi, 8 October: 34.0 µg/m³ Mueang Nonthaburi, 9 October: 17.5 µg/m³ Chaiyaphum Chaiyaphum, 3 October: no reading Chaiyaphum, 4 October: no reading Chaiyaphum, 5 October: no reading Chaiyaphum, 6 October: 25.5 µg/m³, 3.1× its usual 8.2 Chaiyaphum, 7 October: no reading Chaiyaphum, 8 October: no reading Chaiyaphum, 9 October: no reading 3 Oct 4 5 6 7 8 9 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
Ubon Ratchathani Ubon Ratchathani, Thailand 1 6 October 7.0 4.9× Buri Ram Buriram, Thailand 1 6 October 6.2 4.4× Sakon Nakhon Sakon Nakhon, Thailand 1 6 October 7.3 4.0× Surin Surin, Thailand 1 6 October 6.6 4.0× Kanchanaburi Kanchanaburi, Thailand 1 6 October 12.5 3.6× Lop Buri Lopburi, Thailand 1 6 October 8.4 3.4× Mukdahan Mukdahan, Thailand 1 6 October 10.7 3.3× Chaiyaphum Chaiyaphum, Thailand 1 6 October 8.2 3.1× Yasothon Yasothon, Thailand 1 6 October 10.9 2.9× Nakhon Pathom Nakhon Pathom, Thailand 1 6 October 13.1 2.7× Ratchaburi Ratchaburi, Thailand 1 6 October 10.9 2.6× Udon Thani Udon Thani, Thailand 1 6 October 10.1 2.6× Nan Nan, Thailand 1 6 October 11.5 2.5× Nong Khaem Bangkok, Thailand 1 6 October 17.6 2.4× Kalasin Kalasin, Thailand 1 6 October 14.2 2.4× Nakhon Ratchasima Nakhon Ratchasima, Thailand 1 6 October 12.5 2.4× Amnat Charoen Amnat Charoen, Thailand 1 6 October 12.3 2.4× Samut Sakhon Samut Sakhon, Thailand 1 6 October 17.5 2.3× Vientiane Vientiane Prefecture, Laos 1 6 October 16.4 2.3× Sing Buri Sing Buri, Thailand 1 6 October 16.1 2.2× Mueang Nonthaburi Nonthaburi, Thailand 1 6 October 11.8 2.2× Tha Bo Nong Khai, Thailand 1 6 October 17.8 2.1× Ban Samae Dam Bangkok, Thailand 1 6 October 16.8 2.1× Khlong Luang Pathum Thani, Thailand 1 6 October 15.5 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 9 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, Northern Thailand and Laos, October 2024: 24 cities with PM2.5 at twice their usual or more, 6 October 2024, smogrank.com/episodes/2024-10-northern-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.
