SmogRank / Episodes / Thailand
Thailand and Laos, November and December 2025
For 4 days, from 30 November to 3 December 2025, 22 cities in Thailand and Laos had PM2.5 at least twice their usual for the time of year. The worst reading was Mueang Nonthaburi, Nonthaburi, Thailand: 64.0 µg/m³ on 2 December, about 2.3× its usual 27.3.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 22 in 2 countries
Days 4 30 November to 3 December 2025
Worst day 1 December 14 cities counted
Furthest above usual 3.5× Pakxan
Day by day
Play 1 December 14 cities at twice their usual or more
Nakhon Ratchasima Chaiyaphum Buri Ram Saraburi Si Maha Phot Phetchabun Khon Kaen Sing Buri Aranyaprathet Phra Nakhon Si Ayutthaya Maha Sarakham Khlong Luang Khlong Sam Wa Chai Nat Sai Mai Nakhon Sawan Lat Krabang Lak Si Roi Et Bueng Kum Saphan Sung Bang Pakong Uthai Thani Bang Kapi Ban Khlong Prawet Suphan Buri Bang Na Bangkok Nong Khaem Ban Samae Dam Yasothon Loei Ban Talat Bueng Nakhon Pathom Samut Sakhon Udon Thani Chanthaburi Kanchanaburi Ratchaburi Kamphaeng Phet Amnat Charoen Sukhothai Vientiane Ubon Ratchathani Uttaradit Hua Hin Phrae Mae Sot Nan Lampang Lamphun Chrang Chamreh Muoy Chiang Mai Ban Houakhoua Mae Sai Ranong Phayao Nong Chok Phra Pradaeng Khan Na Yao Nong Bua Lamphu Mukdahan Nakhon Nayok Samut Prakan Kalasin Lop Buri Chiang Rai Phetchaburi Si Sa Ket Surin Rayong Phichit Bang Bo District Mueang Nonthaburi Sakon Nakhon Chumphon Ban Chang Pakxan 27 Nov 28 29 30 1 Dec 2 3 4 5 6 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
Pakxan Pakxan, 27 November: 10.7 µg/m³ Pakxan, 28 November: 10.6 µg/m³ Pakxan, 29 November: 14.7 µg/m³ Pakxan, 30 November: 52.3 µg/m³, 3.5× its usual 15.0 Pakxan, 1 December: 51.1 µg/m³, 3.4× its usual 15.0 Pakxan, 2 December: 26.6 µg/m³ Pakxan, 3 December: 19.3 µg/m³ Pakxan, 4 December: 19.2 µg/m³ Pakxan, 5 December: 18.0 µg/m³ Pakxan, 6 December: 15.5 µg/m³ Kalasin Kalasin, 27 November: 37.7 µg/m³ Kalasin, 28 November: 37.9 µg/m³ Kalasin, 29 November: 42.2 µg/m³ Kalasin, 30 November: 51.5 µg/m³, 2.0× its usual 25.2 Kalasin, 1 December: 53.1 µg/m³, 2.1× its usual 24.9 Kalasin, 2 December: 41.9 µg/m³ Kalasin, 3 December: 35.2 µg/m³ Kalasin, 4 December: 25.8 µg/m³ Kalasin, 5 December: 24.9 µg/m³ Kalasin, 6 December: 22.6 µg/m³ Sakon Nakhon Sakon Nakhon, 27 November: 32.3 µg/m³ Sakon Nakhon, 28 November: 28.0 µg/m³ Sakon Nakhon, 29 November: 33.3 µg/m³ Sakon Nakhon, 30 November: 31.7 µg/m³, 2.4× its usual 13.2 Sakon Nakhon, 1 December: 24.6 µg/m³ Sakon Nakhon, 2 December: 15.9 µg/m³ Sakon Nakhon, 3 December: 17.8 µg/m³ Sakon Nakhon, 4 December: 13.5 µg/m³ Sakon Nakhon, 5 December: 14.8 µg/m³ Sakon Nakhon, 6 December: 9.9 µg/m³ Nong Bua Lamphu Nong Bua Lamphu, 27 November: 22.1 µg/m³ Nong Bua Lamphu, 28 November: 19.0 µg/m³ Nong Bua Lamphu, 29 November: 25.5 µg/m³ Nong Bua Lamphu, 30 November: 27.8 µg/m³, 2.1× its usual 13.0 Nong Bua Lamphu, 1 December: 23.8 µg/m³ Nong Bua Lamphu, 2 December: 16.3 µg/m³ Nong Bua Lamphu, 3 December: 19.3 µg/m³ Nong Bua Lamphu, 4 December: 16.9 µg/m³ Nong Bua Lamphu, 5 December: 21.3 µg/m³ Nong Bua Lamphu, 6 December: 24.7 µg/m³ Mueang Nonthaburi Mueang Nonthaburi, 27 November: 38.4 µg/m³ Mueang Nonthaburi, 28 November: 35.2 µg/m³ Mueang Nonthaburi, 29 November: 42.2 µg/m³ Mueang Nonthaburi, 30 November: 55.8 µg/m³ Mueang Nonthaburi, 1 December: 59.9 µg/m³, 2.2× its usual 27.0 Mueang Nonthaburi, 2 December: 64.0 µg/m³, 2.3× its usual 27.3 Mueang Nonthaburi, 3 December: 58.5 µg/m³, 2.1× its usual 27.8 Mueang Nonthaburi, 4 December: 43.5 µg/m³ Mueang Nonthaburi, 5 December: 23.9 µg/m³ Mueang Nonthaburi, 6 December: 28.8 µg/m³ Bang Bo District Bang Bo District, 27 November: 35.5 µg/m³ Bang Bo District, 28 November: 31.6 µg/m³ Bang Bo District, 29 November: 44.8 µg/m³ Bang Bo District, 30 November: 54.6 µg/m³ Bang Bo District, 1 December: 55.2 µg/m³, 2.3× its usual 23.9 Bang Bo District, 2 December: 54.3 µg/m³, 2.1× its usual 25.4 Bang Bo District, 3 December: 58.7 µg/m³, 2.3× its usual 25.8 Bang Bo District, 4 December: no reading Bang Bo District, 5 December: no reading Bang Bo District, 6 December: no reading Phetchaburi Phetchaburi, 27 November: 36.1 µg/m³ Phetchaburi, 28 November: 33.1 µg/m³ Phetchaburi, 29 November: 32.0 µg/m³ Phetchaburi, 30 November: 40.6 µg/m³ Phetchaburi, 1 December: 47.6 µg/m³, 2.2× its usual 21.6 Phetchaburi, 2 December: 48.1 µg/m³, 2.2× its usual 21.8 Phetchaburi, 3 December: 45.9 µg/m³, 2.1× its usual 21.9 Phetchaburi, 4 December: 37.9 µg/m³ Phetchaburi, 5 December: 27.1 µg/m³ Phetchaburi, 6 December: 21.9 µg/m³ Nong Chok Nong Chok, 27 November: 28.6 µg/m³ Nong Chok, 28 November: 26.8 µg/m³ Nong Chok, 29 November: 36.0 µg/m³ Nong Chok, 30 November: 41.1 µg/m³ Nong Chok, 1 December: 43.8 µg/m³, 2.0× its usual 21.7 Nong Chok, 2 December: 44.5 µg/m³, 2.0× its usual 21.8 Nong Chok, 3 December: 42.2 µg/m³ Nong Chok, 4 December: 27.3 µg/m³ Nong Chok, 5 December: 15.4 µg/m³ Nong Chok, 6 December: 21.9 µg/m³ Chumphon Chumphon, 27 November: 28.4 µg/m³ Chumphon, 28 November: 31.4 µg/m³ Chumphon, 29 November: 35.6 µg/m³ Chumphon, 30 November: 39.3 µg/m³ Chumphon, 1 December: 42.7 µg/m³, 2.6× its usual 16.7 Chumphon, 2 December: 36.8 µg/m³, 2.2× its usual 16.8 Chumphon, 3 December: 35.2 µg/m³, 2.1× its usual 16.7 Chumphon, 4 December: 32.0 µg/m³ Chumphon, 5 December: 17.4 µg/m³ Chumphon, 6 December: 9.2 µg/m³ Phichit Phichit, 27 November: 27.2 µg/m³ Phichit, 28 November: 24.8 µg/m³ Phichit, 29 November: 33.5 µg/m³ Phichit, 30 November: 36.7 µg/m³ Phichit, 1 December: 39.9 µg/m³, 2.3× its usual 17.0 Phichit, 2 December: 36.8 µg/m³, 2.1× its usual 17.5 Phichit, 3 December: 35.2 µg/m³ Phichit, 4 December: 32.8 µg/m³ Phichit, 5 December: 37.7 µg/m³ Phichit, 6 December: 35.2 µg/m³ Chiang Rai Chiang Rai, 27 November: 24.8 µg/m³ Chiang Rai, 28 November: 27.2 µg/m³ Chiang Rai, 29 November: 24.4 µg/m³ Chiang Rai, 30 November: 31.0 µg/m³ Chiang Rai, 1 December: 37.7 µg/m³, 2.2× its usual 16.8 Chiang Rai, 2 December: 35.3 µg/m³ Chiang Rai, 3 December: 36.8 µg/m³ Chiang Rai, 4 December: 32.3 µg/m³ Chiang Rai, 5 December: 31.8 µg/m³ Chiang Rai, 6 December: 31.3 µg/m³ Surin Surin, 27 November: 35.0 µg/m³ Surin, 28 November: 23.7 µg/m³ Surin, 29 November: 29.0 µg/m³ Surin, 30 November: 36.4 µg/m³ Surin, 1 December: 34.1 µg/m³, 2.3× its usual 14.8 Surin, 2 December: 23.5 µg/m³ Surin, 3 December: 17.0 µg/m³ Surin, 4 December: 14.3 µg/m³ Surin, 5 December: 12.1 µg/m³ Surin, 6 December: 9.1 µg/m³ Nakhon Nayok Nakhon Nayok, 27 November: 20.4 µg/m³ Nakhon Nayok, 28 November: 19.8 µg/m³ Nakhon Nayok, 29 November: 19.6 µg/m³ Nakhon Nayok, 30 November: 29.0 µg/m³ Nakhon Nayok, 1 December: 32.1 µg/m³, 2.1× its usual 15.1 Nakhon Nayok, 2 December: 28.0 µg/m³ Nakhon Nayok, 3 December: 24.7 µg/m³ Nakhon Nayok, 4 December: 19.8 µg/m³ Nakhon Nayok, 5 December: 12.3 µg/m³ Nakhon Nayok, 6 December: 16.4 µg/m³ Phayao Phayao, 27 November: 24.7 µg/m³ Phayao, 28 November: 22.9 µg/m³ Phayao, 29 November: 25.3 µg/m³ Phayao, 30 November: 28.0 µg/m³ Phayao, 1 December: 31.9 µg/m³, 2.0× its usual 15.9 Phayao, 2 December: 31.4 µg/m³ Phayao, 3 December: 29.9 µg/m³ Phayao, 4 December: 30.3 µg/m³ Phayao, 5 December: 25.2 µg/m³ Phayao, 6 December: 24.5 µg/m³ Mukdahan Mukdahan, 27 November: 29.1 µg/m³ Mukdahan, 28 November: 24.8 µg/m³ Mukdahan, 29 November: 31.0 µg/m³ Mukdahan, 30 November: 25.7 µg/m³ Mukdahan, 1 December: 28.1 µg/m³, 2.1× its usual 13.4 Mukdahan, 2 December: 12.5 µg/m³ Mukdahan, 3 December: 15.2 µg/m³ Mukdahan, 4 December: 14.7 µg/m³ Mukdahan, 5 December: 14.4 µg/m³ Mukdahan, 6 December: 10.7 µg/m³ Si Sa Ket Si Sa Ket, 27 November: 23.3 µg/m³ Si Sa Ket, 28 November: 18.9 µg/m³ Si Sa Ket, 29 November: 20.3 µg/m³ Si Sa Ket, 30 November: 25.7 µg/m³ Si Sa Ket, 1 December: 26.2 µg/m³, 2.3× its usual 11.2 Si Sa Ket, 2 December: 13.4 µg/m³ Si Sa Ket, 3 December: 11.5 µg/m³ Si Sa Ket, 4 December: 10.4 µg/m³ Si Sa Ket, 5 December: 8.1 µg/m³ Si Sa Ket, 6 December: 6.2 µg/m³ Khan Na Yao Khan Na Yao, 27 November: 37.8 µg/m³ Khan Na Yao, 28 November: 38.1 µg/m³ Khan Na Yao, 29 November: 38.7 µg/m³ Khan Na Yao, 30 November: 40.4 µg/m³ Khan Na Yao, 1 December: 45.7 µg/m³ Khan Na Yao, 2 December: 58.7 µg/m³, 2.0× its usual 28.8 Khan Na Yao, 3 December: 53.4 µg/m³ Khan Na Yao, 4 December: 39.3 µg/m³ Khan Na Yao, 5 December: 20.2 µg/m³ Khan Na Yao, 6 December: 31.5 µg/m³ Phra Pradaeng Phra Pradaeng, 27 November: 33.6 µg/m³ Phra Pradaeng, 28 November: 32.9 µg/m³ Phra Pradaeng, 29 November: 35.7 µg/m³ Phra Pradaeng, 30 November: 43.4 µg/m³ Phra Pradaeng, 1 December: 46.5 µg/m³ Phra Pradaeng, 2 December: 52.9 µg/m³, 2.0× its usual 26.1 Phra Pradaeng, 3 December: 49.2 µg/m³ Phra Pradaeng, 4 December: 38.7 µg/m³ Phra Pradaeng, 5 December: 22.4 µg/m³ Phra Pradaeng, 6 December: 27.1 µg/m³ Samut Prakan Samut Prakan, 27 November: 30.2 µg/m³ Samut Prakan, 28 November: 27.8 µg/m³ Samut Prakan, 29 November: 29.5 µg/m³ Samut Prakan, 30 November: 38.3 µg/m³ Samut Prakan, 1 December: 39.8 µg/m³ Samut Prakan, 2 December: 45.3 µg/m³, 2.1× its usual 22.0 Samut Prakan, 3 December: 40.3 µg/m³ Samut Prakan, 4 December: 28.0 µg/m³ Samut Prakan, 5 December: 12.5 µg/m³ Samut Prakan, 6 December: 17.1 µg/m³ Ban Chang Ban Chang, 27 November: 17.5 µg/m³ Ban Chang, 28 November: 14.3 µg/m³ Ban Chang, 29 November: 17.4 µg/m³ Ban Chang, 30 November: 30.7 µg/m³ Ban Chang, 1 December: 36.8 µg/m³ Ban Chang, 2 December: 46.2 µg/m³ Ban Chang, 3 December: 44.0 µg/m³, 2.8× its usual 15.7 Ban Chang, 4 December: 36.7 µg/m³ Ban Chang, 5 December: 9.6 µg/m³ Ban Chang, 6 December: 9.2 µg/m³ Rayong Rayong, 27 November: 16.8 µg/m³ Rayong, 28 November: 16.4 µg/m³ Rayong, 29 November: 22.1 µg/m³ Rayong, 30 November: 32.2 µg/m³ Rayong, 1 December: 32.0 µg/m³ Rayong, 2 December: 33.6 µg/m³ Rayong, 3 December: 39.6 µg/m³, 2.3× its usual 17.2 Rayong, 4 December: 27.2 µg/m³ Rayong, 5 December: 11.4 µg/m³ Rayong, 6 December: 11.8 µg/m³ Lop Buri Lop Buri, 27 November: 24.8 µg/m³ Lop Buri, 28 November: 23.3 µg/m³ Lop Buri, 29 November: 27.7 µg/m³ Lop Buri, 30 November: 31.0 µg/m³ Lop Buri, 1 December: 36.2 µg/m³ Lop Buri, 2 December: 35.2 µg/m³ Lop Buri, 3 December: 33.5 µg/m³, 2.2× its usual 15.1 Lop Buri, 4 December: 20.1 µg/m³ Lop Buri, 5 December: no reading Lop Buri, 6 December: no reading 27 Nov 28 29 30 1 Dec 2 3 4 5 6 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
Pakxan Bolikhamsai, Laos 2 30 November 15.0 3.5× Ban Chang Rayong, Thailand 1 3 December 15.7 2.8× Chumphon Chumphon, Thailand 3 1 December 16.7 2.6× Sakon Nakhon Sakon Nakhon, Thailand 1 30 November 13.2 2.4× Mueang Nonthaburi Nonthaburi, Thailand 3 2 December 27.3 2.3× Bang Bo District Samut Prakan, Thailand 3 3 December 25.8 2.3× Phichit Phichit, Thailand 2 1 December 17.0 2.3× Rayong Rayong, Thailand 1 3 December 17.2 2.3× Surin Surin, Thailand 1 1 December 14.8 2.3× Si Sa Ket Si Sa Ket, Thailand 1 1 December 11.2 2.3× Phetchaburi Phetchaburi, Thailand 3 2 December 21.8 2.2× Chiang Rai Chiang Rai, Thailand 1 1 December 16.8 2.2× Lop Buri Lopburi, Thailand 1 3 December 15.1 2.2× Kalasin Kalasin, Thailand 2 1 December 24.9 2.1× Samut Prakan Samut Prakan, Thailand 1 2 December 22.0 2.1× Nakhon Nayok Nakhon Nayok, Thailand 1 1 December 15.1 2.1× Mukdahan Mukdahan, Thailand 1 1 December 13.4 2.1× Nong Bua Lamphu Nong Bua Lamphu, Thailand 1 30 November 13.0 2.1× Khan Na Yao Bangkok, Thailand 1 2 December 28.8 2.0× Phra Pradaeng Samut Prakan, Thailand 1 2 December 26.1 2.0× Nong Chok Bangkok, Thailand 2 2 December 21.8 2.0× Phayao Phayao, Thailand 1 1 December 15.9 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 10 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, November and December 2025: 22 cities with PM2.5 at twice their usual or more, 30 November to 3 December 2025, smogrank.com/episodes/2025-11-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.
