SmogRank / Episodes / Thailand
Western Thailand, April 2023
For 8 days, from 14 to 21 April 2023, 35 cities in Thailand had PM2.5 at least twice their usual for the time of year. The worst reading was Chai Nat, Chai Nat, Thailand: 90.9 µg/m³ on 17 April, about 2.3× its usual 40.3.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 35 in 1 country
Days 8 14 to 21 April 2023
Worst day 16 April 33 cities counted
Furthest above usual 3.3× Samut Prakan
Day by day
Play 16 April 33 cities at twice their usual or more
Si Maha Phot Bang Khun Thian Saraburi Nakhon Ratchasima Kanchanaburi Nakhon Sawan Chaiyaphum Buri Ram Roi Et Si Sa Ket Ubon Ratchathani Khlong Luang Trat Lop Buri Aranyaprathet Khlong Sam Wa Phra Nakhon Si Ayutthaya Sing Buri Khan Na Yao Chai Nat Suphan Buri Bang Bo District Saphan Sung Sai Mai Lat Krabang Bang Na Nong Chok Ratchaburi Bang Kapi Lak Si Ban Talat Bueng Mueang Nonthaburi Phra Pradaeng Ban Chang Nong Khaem Bangkok Bueng Kum Ban Khlong Prawet Ban Samae Dam Samut Sakhon Rayong Nakhon Pathom Laem Chabang Chanthaburi Hua Hin Samut Prakan 11 Apr 12 13 14 15 16 17 18 19 20 21 22 23 24 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
Samut Prakan Samut Prakan, 11 April: 19.4 µg/m³, 1.0× usual Samut Prakan, 12 April: 29.8 µg/m³, 1.6× usual Samut Prakan, 13 April: 40.1 µg/m³, 2.1× usual Samut Prakan, 14 April: 44.1 µg/m³, 2.3× usual Samut Prakan, 15 April: 56.2 µg/m³, 3.0× usual Samut Prakan, 16 April: 63.3 µg/m³, 3.3× usual Samut Prakan, 17 April: 54.3 µg/m³, 2.9× usual Samut Prakan, 18 April: 45.2 µg/m³, 2.4× usual Samut Prakan, 19 April: 43.6 µg/m³, 2.3× usual Samut Prakan, 20 April: 49.5 µg/m³, 2.6× usual Samut Prakan, 21 April: 53.4 µg/m³, 2.8× usual Samut Prakan, 22 April: no reading Samut Prakan, 23 April: no reading Samut Prakan, 24 April: 27.5 µg/m³, 1.5× usual Nakhon Pathom Nakhon Pathom, 11 April: 25.9 µg/m³, 1.2× usual Nakhon Pathom, 12 April: 34.6 µg/m³, 1.6× usual Nakhon Pathom, 13 April: 42.5 µg/m³, 1.9× usual Nakhon Pathom, 14 April: 46.4 µg/m³, 2.1× usual Nakhon Pathom, 15 April: 61.9 µg/m³, 2.8× usual Nakhon Pathom, 16 April: 63.1 µg/m³, 2.9× usual Nakhon Pathom, 17 April: 52.5 µg/m³, 2.4× usual Nakhon Pathom, 18 April: 48.0 µg/m³, 2.2× usual Nakhon Pathom, 19 April: 46.1 µg/m³, 2.1× usual Nakhon Pathom, 20 April: 49.0 µg/m³, 2.2× usual Nakhon Pathom, 21 April: 50.8 µg/m³, 2.3× usual Nakhon Pathom, 22 April: no reading Nakhon Pathom, 23 April: no reading Nakhon Pathom, 24 April: 31.1 µg/m³, 1.4× usual Bangkok Bangkok, 11 April: 25.6 µg/m³, 1.1× usual Bangkok, 12 April: 35.4 µg/m³, 1.6× usual Bangkok, 13 April: 41.8 µg/m³, 1.8× usual Bangkok, 14 April: 46.0 µg/m³, 2.0× usual Bangkok, 15 April: 55.1 µg/m³, 2.4× usual Bangkok, 16 April: 59.1 µg/m³, 2.6× usual Bangkok, 17 April: 50.1 µg/m³, 2.2× usual Bangkok, 18 April: 48.3 µg/m³, 2.1× usual Bangkok, 19 April: 46.1 µg/m³, 2.0× usual Bangkok, 20 April: 47.6 µg/m³, 2.1× usual Bangkok, 21 April: 51.4 µg/m³, 2.3× usual Bangkok, 22 April: no reading Bangkok, 23 April: no reading Bangkok, 24 April: 28.5 µg/m³, 1.3× usual Samut Sakhon Samut Sakhon, 11 April: 22.6 µg/m³, 1.1× usual Samut Sakhon, 12 April: 28.4 µg/m³, 1.4× usual Samut Sakhon, 13 April: 35.6 µg/m³, 1.7× usual Samut Sakhon, 14 April: 40.8 µg/m³, 2.0× usual Samut Sakhon, 15 April: 49.9 µg/m³, 2.4× usual Samut Sakhon, 16 April: 56.5 µg/m³, 2.7× usual Samut Sakhon, 17 April: 48.4 µg/m³, 2.3× usual Samut Sakhon, 18 April: 43.3 µg/m³, 2.1× usual Samut Sakhon, 19 April: 44.3 µg/m³, 2.1× usual Samut Sakhon, 20 April: 43.9 µg/m³, 2.1× usual Samut Sakhon, 21 April: 47.2 µg/m³, 2.3× usual Samut Sakhon, 22 April: no reading Samut Sakhon, 23 April: no reading Samut Sakhon, 24 April: 21.4 µg/m³, 1.0× usual Nong Khaem Nong Khaem, 11 April: 27.6 µg/m³, 1.1× usual Nong Khaem, 12 April: 36.8 µg/m³, 1.5× usual Nong Khaem, 13 April: 41.7 µg/m³, 1.7× usual Nong Khaem, 14 April: 45.2 µg/m³, 1.9× usual Nong Khaem, 15 April: 53.5 µg/m³, 2.2× usual Nong Khaem, 16 April: 64.1 µg/m³, 2.6× usual Nong Khaem, 17 April: 54.9 µg/m³, 2.3× usual Nong Khaem, 18 April: 50.5 µg/m³, 2.1× usual Nong Khaem, 19 April: 47.4 µg/m³, 2.0× usual Nong Khaem, 20 April: 52.6 µg/m³, 2.2× usual Nong Khaem, 21 April: 56.7 µg/m³, 2.3× usual Nong Khaem, 22 April: no reading Nong Khaem, 23 April: no reading Nong Khaem, 24 April: 30.8 µg/m³, 1.3× usual Mueang Nonthaburi Mueang Nonthaburi, 11 April: 23.3 µg/m³, 1.1× usual Mueang Nonthaburi, 12 April: 34.5 µg/m³, 1.6× usual Mueang Nonthaburi, 13 April: 38.5 µg/m³, 1.8× usual Mueang Nonthaburi, 14 April: 41.4 µg/m³, 1.9× usual Mueang Nonthaburi, 15 April: 49.5 µg/m³, 2.3× usual Mueang Nonthaburi, 16 April: 54.0 µg/m³, 2.5× usual Mueang Nonthaburi, 17 April: 45.4 µg/m³, 2.1× usual Mueang Nonthaburi, 18 April: 41.0 µg/m³, 1.9× usual Mueang Nonthaburi, 19 April: 41.9 µg/m³, 1.9× usual Mueang Nonthaburi, 20 April: 44.8 µg/m³, 2.0× usual Mueang Nonthaburi, 21 April: 47.8 µg/m³, 2.2× usual Mueang Nonthaburi, 22 April: no reading Mueang Nonthaburi, 23 April: no reading Mueang Nonthaburi, 24 April: 25.5 µg/m³, 1.2× usual Phra Pradaeng Phra Pradaeng, 11 April: 19.3 µg/m³, 0.9× usual Phra Pradaeng, 12 April: 28.0 µg/m³, 1.3× usual Phra Pradaeng, 13 April: 35.1 µg/m³, 1.6× usual Phra Pradaeng, 14 April: 42.1 µg/m³, 1.9× usual Phra Pradaeng, 15 April: 48.0 µg/m³, 2.2× usual Phra Pradaeng, 16 April: 55.2 µg/m³, 2.5× usual Phra Pradaeng, 17 April: 45.7 µg/m³, 2.1× usual Phra Pradaeng, 18 April: 41.8 µg/m³, 1.9× usual Phra Pradaeng, 19 April: 42.7 µg/m³, 1.9× usual Phra Pradaeng, 20 April: 45.5 µg/m³, 2.1× usual Phra Pradaeng, 21 April: 48.1 µg/m³, 2.2× usual Phra Pradaeng, 22 April: no reading Phra Pradaeng, 23 April: no reading Phra Pradaeng, 24 April: 25.0 µg/m³, 1.1× usual Bang Kapi Bang Kapi, 11 April: 26.5 µg/m³, 1.2× usual Bang Kapi, 12 April: 34.5 µg/m³, 1.5× usual Bang Kapi, 13 April: 36.1 µg/m³, 1.6× usual Bang Kapi, 14 April: 40.8 µg/m³, 1.8× usual Bang Kapi, 15 April: 46.6 µg/m³, 2.1× usual Bang Kapi, 16 April: 55.5 µg/m³, 2.4× usual Bang Kapi, 17 April: 45.6 µg/m³, 2.0× usual Bang Kapi, 18 April: 40.8 µg/m³, 1.8× usual Bang Kapi, 19 April: 38.0 µg/m³, 1.7× usual Bang Kapi, 20 April: 46.5 µg/m³, 2.0× usual Bang Kapi, 21 April: 48.1 µg/m³, 2.1× usual Bang Kapi, 22 April: no reading Bang Kapi, 23 April: no reading Bang Kapi, 24 April: 29.5 µg/m³, 1.3× usual Bang Bo District Bang Bo District, 11 April: 21.3 µg/m³, 1.0× usual Bang Bo District, 12 April: 28.3 µg/m³, 1.3× usual Bang Bo District, 13 April: 36.3 µg/m³, 1.7× usual Bang Bo District, 14 April: no reading Bang Bo District, 15 April: 43.3 µg/m³, 2.0× usual Bang Bo District, 16 April: 49.2 µg/m³, 2.3× usual Bang Bo District, 17 April: 42.7 µg/m³, 2.0× usual Bang Bo District, 18 April: 37.8 µg/m³, 1.8× usual Bang Bo District, 19 April: 35.5 µg/m³, 1.7× usual Bang Bo District, 20 April: no reading Bang Bo District, 21 April: no reading Bang Bo District, 22 April: no reading Bang Bo District, 23 April: no reading Bang Bo District, 24 April: 30.2 µg/m³, 1.4× usual Sing Buri Sing Buri, 11 April: 47.0 µg/m³, 1.2× usual Sing Buri, 12 April: 62.1 µg/m³, 1.6× usual Sing Buri, 13 April: no reading Sing Buri, 14 April: no reading Sing Buri, 15 April: no reading Sing Buri, 16 April: 84.3 µg/m³, 2.2× usual Sing Buri, 17 April: 83.0 µg/m³, 2.2× usual Sing Buri, 18 April: no reading Sing Buri, 19 April: no reading Sing Buri, 20 April: 61.6 µg/m³, 1.6× usual Sing Buri, 21 April: 69.6 µg/m³, 1.8× usual Sing Buri, 22 April: no reading Sing Buri, 23 April: no reading Sing Buri, 24 April: 58.7 µg/m³, 1.5× usual Chai Nat Chai Nat, 11 April: 43.7 µg/m³, 1.1× usual Chai Nat, 12 April: 65.3 µg/m³, 1.6× usual Chai Nat, 13 April: no reading Chai Nat, 14 April: no reading Chai Nat, 15 April: no reading Chai Nat, 16 April: 83.4 µg/m³, 2.1× usual Chai Nat, 17 April: 90.9 µg/m³, 2.3× usual Chai Nat, 18 April: no reading Chai Nat, 19 April: no reading Chai Nat, 20 April: 63.5 µg/m³, 1.6× usual Chai Nat, 21 April: 66.0 µg/m³, 1.6× usual Chai Nat, 22 April: no reading Chai Nat, 23 April: no reading Chai Nat, 24 April: 55.8 µg/m³, 1.4× usual Suphan Buri Suphan Buri, 11 April: 35.9 µg/m³, 1.1× usual Suphan Buri, 12 April: 50.2 µg/m³, 1.5× usual Suphan Buri, 13 April: no reading Suphan Buri, 14 April: no reading Suphan Buri, 15 April: no reading Suphan Buri, 16 April: 77.8 µg/m³, 2.3× usual Suphan Buri, 17 April: 78.0 µg/m³, 2.3× usual Suphan Buri, 18 April: no reading Suphan Buri, 19 April: no reading Suphan Buri, 20 April: 57.4 µg/m³, 1.7× usual Suphan Buri, 21 April: 68.9 µg/m³, 2.0× usual Suphan Buri, 22 April: no reading Suphan Buri, 23 April: no reading Suphan Buri, 24 April: 52.5 µg/m³, 1.6× usual Lop Buri Lop Buri, 11 April: 42.5 µg/m³, 1.2× usual Lop Buri, 12 April: 53.8 µg/m³, 1.5× usual Lop Buri, 13 April: no reading Lop Buri, 14 April: no reading Lop Buri, 15 April: no reading Lop Buri, 16 April: 72.1 µg/m³, 2.1× usual Lop Buri, 17 April: 59.4 µg/m³, 1.7× usual Lop Buri, 18 April: no reading Lop Buri, 19 April: no reading Lop Buri, 20 April: 62.0 µg/m³, 1.8× usual Lop Buri, 21 April: 68.7 µg/m³, 2.0× usual Lop Buri, 22 April: no reading Lop Buri, 23 April: no reading Lop Buri, 24 April: 45.4 µg/m³, 1.3× usual Ratchaburi Ratchaburi, 11 April: 34.8 µg/m³, 1.2× usual Ratchaburi, 12 April: 42.7 µg/m³, 1.4× usual Ratchaburi, 13 April: no reading Ratchaburi, 14 April: no reading Ratchaburi, 15 April: no reading Ratchaburi, 16 April: 70.8 µg/m³, 2.4× usual Ratchaburi, 17 April: 62.0 µg/m³, 2.1× usual Ratchaburi, 18 April: no reading Ratchaburi, 19 April: no reading Ratchaburi, 20 April: 53.7 µg/m³, 1.8× usual Ratchaburi, 21 April: 52.6 µg/m³, 1.8× usual Ratchaburi, 22 April: no reading Ratchaburi, 23 April: no reading Ratchaburi, 24 April: 39.1 µg/m³, 1.3× usual Bang Na Bang Na, 11 April: 33.9 µg/m³, 1.2× usual Bang Na, 12 April: 43.4 µg/m³, 1.6× usual Bang Na, 13 April: no reading Bang Na, 14 April: no reading Bang Na, 15 April: no reading Bang Na, 16 April: 65.5 µg/m³, 2.4× usual Bang Na, 17 April: 56.6 µg/m³, 2.1× usual Bang Na, 18 April: no reading Bang Na, 19 April: no reading Bang Na, 20 April: 56.8 µg/m³, 2.1× usual Bang Na, 21 April: 60.6 µg/m³, 2.2× usual Bang Na, 22 April: no reading Bang Na, 23 April: no reading Bang Na, 24 April: 36.9 µg/m³, 1.3× usual Hua Hin Hua Hin, 11 April: 27.9 µg/m³, 1.3× usual Hua Hin, 12 April: 39.1 µg/m³, 1.8× usual Hua Hin, 13 April: no reading Hua Hin, 14 April: no reading Hua Hin, 15 April: no reading Hua Hin, 16 April: 64.3 µg/m³, 3.0× usual Hua Hin, 17 April: 49.9 µg/m³, 2.4× usual Hua Hin, 18 April: no reading Hua Hin, 19 April: no reading Hua Hin, 20 April: 50.2 µg/m³, 2.4× usual Hua Hin, 21 April: 44.4 µg/m³, 2.1× usual Hua Hin, 22 April: no reading Hua Hin, 23 April: no reading Hua Hin, 24 April: 31.8 µg/m³, 1.5× usual Ban Samae Dam Ban Samae Dam, 11 April: 27.1 µg/m³, 1.2× usual Ban Samae Dam, 12 April: 37.0 µg/m³, 1.6× usual Ban Samae Dam, 13 April: no reading Ban Samae Dam, 14 April: no reading Ban Samae Dam, 15 April: no reading Ban Samae Dam, 16 April: 62.3 µg/m³, 2.7× usual Ban Samae Dam, 17 April: 51.5 µg/m³, 2.2× usual Ban Samae Dam, 18 April: no reading Ban Samae Dam, 19 April: no reading Ban Samae Dam, 20 April: 50.1 µg/m³, 2.2× usual Ban Samae Dam, 21 April: 54.0 µg/m³, 2.3× usual Ban Samae Dam, 22 April: no reading Ban Samae Dam, 23 April: no reading Ban Samae Dam, 24 April: 30.0 µg/m³, 1.3× usual Phra Nakhon Si Ayut… Phra Nakhon Si Ayutthaya, 11 April: 26.7 µg/m³, 1.0× usual Phra Nakhon Si Ayutthaya, 12 April: 40.8 µg/m³, 1.5× usual Phra Nakhon Si Ayutthaya, 13 April: no reading Phra Nakhon Si Ayutthaya, 14 April: no reading Phra Nakhon Si Ayutthaya, 15 April: no reading Phra Nakhon Si Ayutthaya, 16 April: 60.1 µg/m³, 2.2× usual Phra Nakhon Si Ayutthaya, 17 April: 56.7 µg/m³, 2.0× usual Phra Nakhon Si Ayutthaya, 18 April: no reading Phra Nakhon Si Ayutthaya, 19 April: no reading Phra Nakhon Si Ayutthaya, 20 April: 49.3 µg/m³, 1.8× usual Phra Nakhon Si Ayutthaya, 21 April: 57.3 µg/m³, 2.1× usual Phra Nakhon Si Ayutthaya, 22 April: no reading Phra Nakhon Si Ayutthaya, 23 April: no reading Phra Nakhon Si Ayutthaya, 24 April: 41.0 µg/m³, 1.5× usual Khlong Sam Wa Khlong Sam Wa, 11 April: 29.5 µg/m³, 1.1× usual Khlong Sam Wa, 12 April: 40.2 µg/m³, 1.5× usual Khlong Sam Wa, 13 April: no reading Khlong Sam Wa, 14 April: no reading Khlong Sam Wa, 15 April: no reading Khlong Sam Wa, 16 April: 60.0 µg/m³, 2.2× usual Khlong Sam Wa, 17 April: 54.6 µg/m³, 2.0× usual Khlong Sam Wa, 18 April: no reading Khlong Sam Wa, 19 April: no reading Khlong Sam Wa, 20 April: 52.3 µg/m³, 2.0× usual Khlong Sam Wa, 21 April: 54.7 µg/m³, 2.0× usual Khlong Sam Wa, 22 April: no reading Khlong Sam Wa, 23 April: no reading Khlong Sam Wa, 24 April: 35.5 µg/m³, 1.3× usual Bueng Kum Bueng Kum, 11 April: 24.3 µg/m³, 1.1× usual Bueng Kum, 12 April: 35.3 µg/m³, 1.7× usual Bueng Kum, 13 April: no reading Bueng Kum, 14 April: no reading Bueng Kum, 15 April: no reading Bueng Kum, 16 April: 57.7 µg/m³, 2.7× usual Bueng Kum, 17 April: 52.0 µg/m³, 2.5× usual Bueng Kum, 18 April: no reading Bueng Kum, 19 April: no reading Bueng Kum, 20 April: 49.3 µg/m³, 2.3× usual Bueng Kum, 21 April: 51.3 µg/m³, 2.4× usual Bueng Kum, 22 April: no reading Bueng Kum, 23 April: no reading Bueng Kum, 24 April: 30.5 µg/m³, 1.4× usual Lak Si Lak Si, 11 April: 25.6 µg/m³, 1.1× usual Lak Si, 12 April: 35.8 µg/m³, 1.5× usual Lak Si, 13 April: no reading Lak Si, 14 April: no reading Lak Si, 15 April: no reading Lak Si, 16 April: 57.7 µg/m³, 2.5× usual Lak Si, 17 April: 49.9 µg/m³, 2.1× usual Lak Si, 18 April: no reading Lak Si, 19 April: no reading Lak Si, 20 April: 48.0 µg/m³, 2.0× usual Lak Si, 21 April: 50.3 µg/m³, 2.1× usual Lak Si, 22 April: no reading Lak Si, 23 April: no reading Lak Si, 24 April: 28.3 µg/m³, 1.2× usual Saphan Sung Saphan Sung, 11 April: 25.7 µg/m³, 1.1× usual Saphan Sung, 12 April: 35.5 µg/m³, 1.5× usual Saphan Sung, 13 April: no reading Saphan Sung, 14 April: no reading Saphan Sung, 15 April: no reading Saphan Sung, 16 April: 57.2 µg/m³, 2.4× usual Saphan Sung, 17 April: 49.8 µg/m³, 2.1× usual Saphan Sung, 18 April: no reading Saphan Sung, 19 April: no reading Saphan Sung, 20 April: 47.0 µg/m³, 2.0× usual Saphan Sung, 21 April: 48.8 µg/m³, 2.0× usual Saphan Sung, 22 April: no reading Saphan Sung, 23 April: no reading Saphan Sung, 24 April: no reading Khan Na Yao Khan Na Yao, 11 April: 24.9 µg/m³, 1.0× usual Khan Na Yao, 12 April: 38.4 µg/m³, 1.5× usual Khan Na Yao, 13 April: no reading Khan Na Yao, 14 April: no reading Khan Na Yao, 15 April: no reading Khan Na Yao, 16 April: 57.0 µg/m³, 2.3× usual Khan Na Yao, 17 April: 53.5 µg/m³, 2.2× usual Khan Na Yao, 18 April: no reading Khan Na Yao, 19 April: no reading Khan Na Yao, 20 April: 50.0 µg/m³, 2.0× usual Khan Na Yao, 21 April: 52.7 µg/m³, 2.1× usual Khan Na Yao, 22 April: no reading Khan Na Yao, 23 April: no reading Khan Na Yao, 24 April: 33.2 µg/m³, 1.3× usual Sai Mai Sai Mai, 11 April: 26.0 µg/m³, 1.1× usual Sai Mai, 12 April: 35.9 µg/m³, 1.5× usual Sai Mai, 13 April: no reading Sai Mai, 14 April: no reading Sai Mai, 15 April: no reading Sai Mai, 16 April: 55.3 µg/m³, 2.4× usual Sai Mai, 17 April: 47.4 µg/m³, 2.0× usual Sai Mai, 18 April: no reading Sai Mai, 19 April: no reading Sai Mai, 20 April: 45.0 µg/m³, 1.9× usual Sai Mai, 21 April: 47.6 µg/m³, 2.1× usual Sai Mai, 22 April: no reading Sai Mai, 23 April: no reading Sai Mai, 24 April: 28.0 µg/m³, 1.2× usual Lat Krabang Lat Krabang, 11 April: 21.6 µg/m³, 0.9× usual Lat Krabang, 12 April: 32.3 µg/m³, 1.4× usual Lat Krabang, 13 April: no reading Lat Krabang, 14 April: no reading Lat Krabang, 15 April: no reading Lat Krabang, 16 April: 55.2 µg/m³, 2.4× usual Lat Krabang, 17 April: 50.4 µg/m³, 2.2× usual Lat Krabang, 18 April: no reading Lat Krabang, 19 April: no reading Lat Krabang, 20 April: 46.5 µg/m³, 2.0× usual Lat Krabang, 21 April: 48.3 µg/m³, 2.1× usual Lat Krabang, 22 April: no reading Lat Krabang, 23 April: no reading Lat Krabang, 24 April: 30.1 µg/m³, 1.3× usual Ban Chang Ban Chang, 11 April: 23.1 µg/m³, 1.1× usual Ban Chang, 12 April: 33.1 µg/m³, 1.6× usual Ban Chang, 13 April: no reading Ban Chang, 14 April: no reading Ban Chang, 15 April: no reading Ban Chang, 16 April: 54.7 µg/m³, 2.6× usual Ban Chang, 17 April: 51.8 µg/m³, 2.4× usual Ban Chang, 18 April: no reading Ban Chang, 19 April: no reading Ban Chang, 20 April: 52.6 µg/m³, 2.5× usual Ban Chang, 21 April: 49.2 µg/m³, 2.3× usual Ban Chang, 22 April: no reading Ban Chang, 23 April: no reading Ban Chang, 24 April: 29.2 µg/m³, 1.4× usual Nong Chok Nong Chok, 11 April: 22.7 µg/m³, 1.0× usual Nong Chok, 12 April: 36.3 µg/m³, 1.6× usual Nong Chok, 13 April: no reading Nong Chok, 14 April: no reading Nong Chok, 15 April: no reading Nong Chok, 16 April: 54.4 µg/m³, 2.4× usual Nong Chok, 17 April: 48.7 µg/m³, 2.1× usual Nong Chok, 18 April: no reading Nong Chok, 19 April: no reading Nong Chok, 20 April: 46.2 µg/m³, 2.0× usual Nong Chok, 21 April: 48.4 µg/m³, 2.1× usual Nong Chok, 22 April: no reading Nong Chok, 23 April: no reading Nong Chok, 24 April: no reading Ban Khlong Prawet Ban Khlong Prawet, 11 April: 22.0 µg/m³, 1.1× usual Ban Khlong Prawet, 12 April: 31.2 µg/m³, 1.6× usual Ban Khlong Prawet, 13 April: no reading Ban Khlong Prawet, 14 April: no reading Ban Khlong Prawet, 15 April: no reading Ban Khlong Prawet, 16 April: 53.9 µg/m³, 2.7× usual Ban Khlong Prawet, 17 April: 45.5 µg/m³, 2.3× usual Ban Khlong Prawet, 18 April: no reading Ban Khlong Prawet, 19 April: no reading Ban Khlong Prawet, 20 April: 44.3 µg/m³, 2.2× usual Ban Khlong Prawet, 21 April: 45.7 µg/m³, 2.3× usual Ban Khlong Prawet, 22 April: no reading Ban Khlong Prawet, 23 April: no reading Ban Khlong Prawet, 24 April: 27.5 µg/m³, 1.4× usual Laem Chabang Laem Chabang, 11 April: 26.2 µg/m³, 1.5× usual Laem Chabang, 12 April: 31.1 µg/m³, 1.7× usual Laem Chabang, 13 April: no reading Laem Chabang, 14 April: no reading Laem Chabang, 15 April: no reading Laem Chabang, 16 April: 53.4 µg/m³, 3.0× usual Laem Chabang, 17 April: 48.2 µg/m³, 2.7× usual Laem Chabang, 18 April: no reading Laem Chabang, 19 April: no reading Laem Chabang, 20 April: 44.4 µg/m³, 2.5× usual Laem Chabang, 21 April: 46.2 µg/m³, 2.6× usual Laem Chabang, 22 April: no reading Laem Chabang, 23 April: no reading Laem Chabang, 24 April: 28.6 µg/m³, 1.6× usual Khlong Luang Khlong Luang, 11 April: 22.1 µg/m³, 0.8× usual Khlong Luang, 12 April: 33.8 µg/m³, 1.3× usual Khlong Luang, 13 April: 38.3 µg/m³, 1.5× usual Khlong Luang, 14 April: 38.6 µg/m³, 1.5× usual Khlong Luang, 15 April: 48.0 µg/m³, 1.8× usual Khlong Luang, 16 April: 52.4 µg/m³, 2.0× usual Khlong Luang, 17 April: 47.5 µg/m³, 1.8× usual Khlong Luang, 18 April: 44.9 µg/m³, 1.7× usual Khlong Luang, 19 April: 38.5 µg/m³, 1.5× usual Khlong Luang, 20 April: 44.7 µg/m³, 1.7× usual Khlong Luang, 21 April: 46.8 µg/m³, 1.8× usual Khlong Luang, 22 April: no reading Khlong Luang, 23 April: no reading Khlong Luang, 24 April: 30.8 µg/m³, 1.2× usual Ban Talat Bueng Ban Talat Bueng, 11 April: 20.6 µg/m³, 1.0× usual Ban Talat Bueng, 12 April: 33.9 µg/m³, 1.6× usual Ban Talat Bueng, 13 April: no reading Ban Talat Bueng, 14 April: no reading Ban Talat Bueng, 15 April: no reading Ban Talat Bueng, 16 April: 52.1 µg/m³, 2.5× usual Ban Talat Bueng, 17 April: 44.4 µg/m³, 2.2× usual Ban Talat Bueng, 18 April: no reading Ban Talat Bueng, 19 April: no reading Ban Talat Bueng, 20 April: 42.6 µg/m³, 2.1× usual Ban Talat Bueng, 21 April: 42.8 µg/m³, 2.1× usual Ban Talat Bueng, 22 April: no reading Ban Talat Bueng, 23 April: no reading Ban Talat Bueng, 24 April: 29.7 µg/m³, 1.4× usual Rayong Rayong, 11 April: 20.5 µg/m³, 1.2× usual Rayong, 12 April: 25.8 µg/m³, 1.5× usual Rayong, 13 April: no reading Rayong, 14 April: no reading Rayong, 15 April: no reading Rayong, 16 April: 49.5 µg/m³, 2.9× usual Rayong, 17 April: 46.1 µg/m³, 2.7× usual Rayong, 18 April: no reading Rayong, 19 April: no reading Rayong, 20 April: 39.1 µg/m³, 2.3× usual Rayong, 21 April: 43.8 µg/m³, 2.5× usual Rayong, 22 April: no reading Rayong, 23 April: no reading Rayong, 24 April: 28.7 µg/m³, 1.7× usual Chanthaburi Chanthaburi, 11 April: 17.8 µg/m³, 1.1× usual Chanthaburi, 12 April: 26.7 µg/m³, 1.7× usual Chanthaburi, 13 April: no reading Chanthaburi, 14 April: no reading Chanthaburi, 15 April: no reading Chanthaburi, 16 April: 45.5 µg/m³, 2.9× usual Chanthaburi, 17 April: 36.6 µg/m³, 2.3× usual Chanthaburi, 18 April: no reading Chanthaburi, 19 April: no reading Chanthaburi, 20 April: 33.0 µg/m³, 2.1× usual Chanthaburi, 21 April: 47.3 µg/m³, 3.0× usual Chanthaburi, 22 April: no reading Chanthaburi, 23 April: no reading Chanthaburi, 24 April: 23.6 µg/m³, 1.5× usual Aranyaprathet Aranyaprathet, 11 April: 20.3 µg/m³, 1.1× usual Aranyaprathet, 12 April: 26.1 µg/m³, 1.5× usual Aranyaprathet, 13 April: no reading Aranyaprathet, 14 April: no reading Aranyaprathet, 15 April: no reading Aranyaprathet, 16 April: 33.9 µg/m³, 1.9× usual Aranyaprathet, 17 April: 35.3 µg/m³, 2.0× usual Aranyaprathet, 18 April: no reading Aranyaprathet, 19 April: no reading Aranyaprathet, 20 April: 28.2 µg/m³, 1.6× usual Aranyaprathet, 21 April: 39.6 µg/m³, 2.2× usual Aranyaprathet, 22 April: no reading Aranyaprathet, 23 April: no reading Aranyaprathet, 24 April: 23.1 µg/m³, 1.3× usual Trat Trat, 11 April: 21.0 µg/m³, 1.2× usual Trat, 12 April: 26.2 µg/m³, 1.5× usual Trat, 13 April: no reading Trat, 14 April: no reading Trat, 15 April: no reading Trat, 16 April: 30.9 µg/m³, 1.8× usual Trat, 17 April: 24.4 µg/m³, 1.4× usual Trat, 18 April: no reading Trat, 19 April: no reading Trat, 20 April: 25.4 µg/m³, 1.4× usual Trat, 21 April: 37.6 µg/m³, 2.1× usual Trat, 22 April: no reading Trat, 23 April: no reading Trat, 24 April: 17.7 µg/m³, 1.0× usual 11 Apr 13 15 17 19 21 23 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
Samut Prakan Samut Prakan, Thailand 8 16 April 18.9 3.3× Hua Hin Prachuap Khiri Khan, Thailand 4 16 April 21.2 3.0× Chanthaburi Chanthaburi, Thailand 4 21 April 15.7 3.0× Laem Chabang Chon Buri, Thailand 4 16 April 17.8 3.0× Nakhon Pathom Nakhon Pathom, Thailand 8 16 April 22.0 2.9× Rayong Rayong, Thailand 4 16 April 17.3 2.9× Samut Sakhon Samut Sakhon, Thailand 8 16 April 20.7 2.7× Bueng Kum Bangkok, Thailand 4 16 April 21.2 2.7× Ban Khlong Prawet Bangkok, Thailand 4 16 April 20.0 2.7× Ban Samae Dam Bangkok, Thailand 4 16 April 23.2 2.7× Nong Khaem Bangkok, Thailand 6 16 April 24.2 2.6× Bangkok Bangkok, Thailand 8 16 April 22.6 2.6× Ban Chang Rayong, Thailand 4 16 April 21.3 2.6× Ban Talat Bueng Chon Buri, Thailand 4 16 April 20.6 2.5× Phra Pradaeng Samut Prakan, Thailand 5 16 April 21.9 2.5× Lak Si Bangkok, Thailand 4 16 April 23.5 2.5× Mueang Nonthaburi Nonthaburi, Thailand 5 16 April 22.0 2.5× Bang Kapi Bangkok, Thailand 5 16 April 22.7 2.4× Lat Krabang Bangkok, Thailand 4 16 April 23.0 2.4× Ratchaburi Ratchaburi, Thailand 2 16 April 29.6 2.4× Sai Mai Bangkok, Thailand 3 16 April 23.2 2.4× Saphan Sung Bangkok, Thailand 3 16 April 24.0 2.4× Bang Na Bangkok, Thailand 4 16 April 27.5 2.4× Nong Chok Bangkok, Thailand 4 16 April 23.0 2.4× Suphan Buri Suphan Buri, Thailand 3 17 April 33.7 2.3× Bang Bo District Samut Prakan, Thailand 3 16 April 21.4 2.3× Khan Na Yao Bangkok, Thailand 4 16 April 24.8 2.3× Chai Nat Chai Nat, Thailand 2 17 April 40.3 2.3× Khlong Sam Wa Bangkok, Thailand 3 16 April 26.8 2.2× Sing Buri Sing Buri, Thailand 2 16 April 38.0 2.2× Aranyaprathet Sa Kaeo, Thailand 1 21 April 17.9 2.2× Phra Nakhon Si Ayutthaya Phra Nakhon Si Ayutthaya, Thailand 3 16 April 27.7 2.2× Trat Trat, Thailand 1 21 April 17.6 2.1× Lop Buri Lopburi, Thailand 2 16 April 35.0 2.1× Khlong Luang Pathum Thani, Thailand 1 16 April 26.2 2.0×
Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.
Against other episodes in Thailand
Number 6 of 24 episodes in Thailand since our records began, by cities reached.
Central Thailand, March 2025 53 Western Thailand, February 2024 51 Central Thailand, January 2025 50 North-western Thailand, April and May 2024 45 North-western Thailand, May 2023 41 Western Thailand, April 2023 35 Western Thailand and Laos, January and February 2023 34 North-western Thailand, May 2023 30 North-eastern Thailand, October 2024 24 Northern Thailand, November and December 2025 22 Western Thailand, February 2025 17 North-western Thailand, May 2023 17 Bars: cities reached; colour: the level of the episode's highest daily reading. All 24 .
Use this page SmogRank, Western Thailand, April 2023: 35 cities with PM2.5 at twice their usual or more, 14 to 21 April 2023, smogrank.com/episodes/2023-04-western-thailand (accessed 3 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.
