SmogRank / Episodes / Thailand
Northern Thailand, 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 Khan Na Yao Phra Pradaeng Nong Chok Phayao Samut Prakan Mukdahan Nakhon Nayok Kalasin Nong Bua Lamphu Lop Buri Chiang Rai Phetchaburi Rayong Bang Bo District Mueang Nonthaburi Phichit Si Sa Ket Surin 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
Mueang Nonthaburi Mueang Nonthaburi, 27 November: 38.4 µg/m³, 1.4× usual Mueang Nonthaburi, 28 November: 35.2 µg/m³, 1.3× usual Mueang Nonthaburi, 29 November: 42.2 µg/m³, 1.5× usual Mueang Nonthaburi, 30 November: 55.8 µg/m³, 2.0× usual Mueang Nonthaburi, 1 December: 59.9 µg/m³, 2.2× usual Mueang Nonthaburi, 2 December: 64.0 µg/m³, 2.3× usual Mueang Nonthaburi, 3 December: 58.5 µg/m³, 2.1× usual Mueang Nonthaburi, 4 December: 43.5 µg/m³, 1.6× usual Mueang Nonthaburi, 5 December: 23.9 µg/m³, 0.9× usual Mueang Nonthaburi, 6 December: 28.8 µg/m³, 1.1× usual Bang Bo District Bang Bo District, 27 November: 35.5 µg/m³, 1.4× usual Bang Bo District, 28 November: 31.6 µg/m³, 1.2× usual Bang Bo District, 29 November: 44.8 µg/m³, 1.7× usual Bang Bo District, 30 November: 54.6 µg/m³, 2.1× usual Bang Bo District, 1 December: 55.2 µg/m³, 2.1× usual Bang Bo District, 2 December: 54.3 µg/m³, 2.1× usual Bang Bo District, 3 December: 58.7 µg/m³, 2.3× usual Bang Bo District, 4 December: no reading Bang Bo District, 5 December: no reading Bang Bo District, 6 December: no reading Pakxan Pakxan, 27 November: 10.7 µg/m³, 0.7× usual Pakxan, 28 November: 10.6 µg/m³, 0.7× usual Pakxan, 29 November: 14.7 µg/m³, 1.0× usual Pakxan, 30 November: 52.3 µg/m³, 3.5× usual Pakxan, 1 December: 51.1 µg/m³, 3.4× usual Pakxan, 2 December: 26.6 µg/m³, 1.8× usual Pakxan, 3 December: 19.3 µg/m³, 1.3× usual Pakxan, 4 December: 19.2 µg/m³, 1.3× usual Pakxan, 5 December: 18.0 µg/m³, 1.2× usual Pakxan, 6 December: 15.5 µg/m³, 1.0× usual Kalasin Kalasin, 27 November: 37.7 µg/m³, 1.5× usual Kalasin, 28 November: 37.9 µg/m³, 1.5× usual Kalasin, 29 November: 42.2 µg/m³, 1.7× usual Kalasin, 30 November: 51.5 µg/m³, 2.1× usual Kalasin, 1 December: 53.1 µg/m³, 2.1× usual Kalasin, 2 December: 41.9 µg/m³, 1.7× usual Kalasin, 3 December: 35.2 µg/m³, 1.4× usual Kalasin, 4 December: 25.8 µg/m³, 1.0× usual Kalasin, 5 December: 24.9 µg/m³, 1.0× usual Kalasin, 6 December: 22.6 µg/m³, 0.9× usual Chumphon Chumphon, 27 November: 28.4 µg/m³, 1.7× usual Chumphon, 28 November: 31.4 µg/m³, 1.9× usual Chumphon, 29 November: 35.6 µg/m³, 2.1× usual Chumphon, 30 November: 39.3 µg/m³, 2.4× usual Chumphon, 1 December: 42.7 µg/m³, 2.6× usual Chumphon, 2 December: 36.8 µg/m³, 2.2× usual Chumphon, 3 December: 35.2 µg/m³, 2.1× usual Chumphon, 4 December: 32.0 µg/m³, 1.9× usual Chumphon, 5 December: 17.4 µg/m³, 1.0× usual Chumphon, 6 December: 9.2 µg/m³, 0.6× usual Sakon Nakhon Sakon Nakhon, 27 November: 32.3 µg/m³, 2.4× usual Sakon Nakhon, 28 November: 28.0 µg/m³, 2.1× usual Sakon Nakhon, 29 November: 33.3 µg/m³, 2.5× usual Sakon Nakhon, 30 November: 31.7 µg/m³, 2.4× usual Sakon Nakhon, 1 December: 24.6 µg/m³, 1.9× usual Sakon Nakhon, 2 December: 15.9 µg/m³, 1.2× usual Sakon Nakhon, 3 December: 17.8 µg/m³, 1.3× usual Sakon Nakhon, 4 December: 13.5 µg/m³, 1.0× usual Sakon Nakhon, 5 December: 14.8 µg/m³, 1.1× usual Sakon Nakhon, 6 December: 9.9 µg/m³, 0.8× usual Nong Bua Lamphu Nong Bua Lamphu, 27 November: 22.1 µg/m³, 1.7× usual Nong Bua Lamphu, 28 November: 19.0 µg/m³, 1.5× usual Nong Bua Lamphu, 29 November: 25.5 µg/m³, 2.0× usual Nong Bua Lamphu, 30 November: 27.8 µg/m³, 2.1× usual Nong Bua Lamphu, 1 December: 23.8 µg/m³, 1.8× usual Nong Bua Lamphu, 2 December: 16.3 µg/m³, 1.3× usual Nong Bua Lamphu, 3 December: 19.3 µg/m³, 1.5× usual Nong Bua Lamphu, 4 December: 16.9 µg/m³, 1.3× usual Nong Bua Lamphu, 5 December: 21.3 µg/m³, 1.6× usual Nong Bua Lamphu, 6 December: 24.7 µg/m³, 1.9× usual Phetchaburi Phetchaburi, 27 November: 36.1 µg/m³, 1.7× usual Phetchaburi, 28 November: 33.1 µg/m³, 1.5× usual Phetchaburi, 29 November: 32.0 µg/m³, 1.5× usual Phetchaburi, 30 November: 40.6 µg/m³, 1.9× usual Phetchaburi, 1 December: 47.6 µg/m³, 2.2× usual Phetchaburi, 2 December: 48.1 µg/m³, 2.2× usual Phetchaburi, 3 December: 45.9 µg/m³, 2.1× usual Phetchaburi, 4 December: 37.9 µg/m³, 1.7× usual Phetchaburi, 5 December: 27.1 µg/m³, 1.2× usual Phetchaburi, 6 December: 21.9 µg/m³, 1.0× usual Nong Chok Nong Chok, 27 November: 28.6 µg/m³, 1.3× usual Nong Chok, 28 November: 26.8 µg/m³, 1.2× usual Nong Chok, 29 November: 36.0 µg/m³, 1.7× usual Nong Chok, 30 November: 41.1 µg/m³, 1.9× usual Nong Chok, 1 December: 43.8 µg/m³, 2.0× usual Nong Chok, 2 December: 44.5 µg/m³, 2.0× usual Nong Chok, 3 December: 42.2 µg/m³, 1.9× usual Nong Chok, 4 December: 27.3 µg/m³, 1.3× usual Nong Chok, 5 December: 15.4 µg/m³, 0.7× usual Nong Chok, 6 December: 21.9 µg/m³, 1.0× usual Phichit Phichit, 27 November: 27.2 µg/m³, 1.6× usual Phichit, 28 November: 24.8 µg/m³, 1.5× usual Phichit, 29 November: 33.5 µg/m³, 2.0× usual Phichit, 30 November: 36.7 µg/m³, 2.2× usual Phichit, 1 December: 39.9 µg/m³, 2.3× usual Phichit, 2 December: 36.8 µg/m³, 2.2× usual Phichit, 3 December: 35.2 µg/m³, 2.1× usual Phichit, 4 December: 32.8 µg/m³, 1.9× usual Phichit, 5 December: 37.7 µg/m³, 2.2× usual Phichit, 6 December: 35.2 µg/m³, 2.1× usual Chiang Rai Chiang Rai, 27 November: 24.8 µg/m³, 1.5× usual Chiang Rai, 28 November: 27.2 µg/m³, 1.6× usual Chiang Rai, 29 November: 24.4 µg/m³, 1.5× usual Chiang Rai, 30 November: 31.0 µg/m³, 1.8× usual Chiang Rai, 1 December: 37.7 µg/m³, 2.2× usual Chiang Rai, 2 December: 35.3 µg/m³, 2.1× usual Chiang Rai, 3 December: 36.8 µg/m³, 2.2× usual Chiang Rai, 4 December: 32.3 µg/m³, 1.9× usual Chiang Rai, 5 December: 31.8 µg/m³, 1.9× usual Chiang Rai, 6 December: 31.3 µg/m³, 1.9× usual Surin Surin, 27 November: 35.0 µg/m³, 2.4× usual Surin, 28 November: 23.7 µg/m³, 1.6× usual Surin, 29 November: 29.0 µg/m³, 2.0× usual Surin, 30 November: 36.4 µg/m³, 2.5× usual Surin, 1 December: 34.1 µg/m³, 2.3× usual Surin, 2 December: 23.5 µg/m³, 1.6× usual Surin, 3 December: 17.0 µg/m³, 1.1× usual Surin, 4 December: 14.3 µg/m³, 1.0× usual Surin, 5 December: 12.1 µg/m³, 0.8× usual Surin, 6 December: 9.1 µg/m³, 0.6× usual Nakhon Nayok Nakhon Nayok, 27 November: 20.4 µg/m³, 1.4× usual Nakhon Nayok, 28 November: 19.8 µg/m³, 1.3× usual Nakhon Nayok, 29 November: 19.6 µg/m³, 1.3× usual Nakhon Nayok, 30 November: 29.0 µg/m³, 1.9× usual Nakhon Nayok, 1 December: 32.1 µg/m³, 2.1× usual Nakhon Nayok, 2 December: 28.0 µg/m³, 1.9× usual Nakhon Nayok, 3 December: 24.7 µg/m³, 1.6× usual Nakhon Nayok, 4 December: 19.8 µg/m³, 1.3× usual Nakhon Nayok, 5 December: 12.3 µg/m³, 0.8× usual Nakhon Nayok, 6 December: 16.4 µg/m³, 1.1× usual Phayao Phayao, 27 November: 24.7 µg/m³, 1.6× usual Phayao, 28 November: 22.9 µg/m³, 1.4× usual Phayao, 29 November: 25.3 µg/m³, 1.6× usual Phayao, 30 November: 28.0 µg/m³, 1.8× usual Phayao, 1 December: 31.9 µg/m³, 2.0× usual Phayao, 2 December: 31.4 µg/m³, 2.0× usual Phayao, 3 December: 29.9 µg/m³, 1.9× usual Phayao, 4 December: 30.3 µg/m³, 1.9× usual Phayao, 5 December: 25.2 µg/m³, 1.6× usual Phayao, 6 December: 24.5 µg/m³, 1.5× usual Mukdahan Mukdahan, 27 November: 29.1 µg/m³, 2.2× usual Mukdahan, 28 November: 24.8 µg/m³, 1.9× usual Mukdahan, 29 November: 31.0 µg/m³, 2.3× usual Mukdahan, 30 November: 25.7 µg/m³, 1.9× usual Mukdahan, 1 December: 28.1 µg/m³, 2.1× usual Mukdahan, 2 December: 12.5 µg/m³, 0.9× usual Mukdahan, 3 December: 15.2 µg/m³, 1.1× usual Mukdahan, 4 December: 14.7 µg/m³, 1.1× usual Mukdahan, 5 December: 14.4 µg/m³, 1.1× usual Mukdahan, 6 December: 10.7 µg/m³, 0.8× usual Si Sa Ket Si Sa Ket, 27 November: 23.3 µg/m³, 2.1× usual Si Sa Ket, 28 November: 18.9 µg/m³, 1.7× usual Si Sa Ket, 29 November: 20.3 µg/m³, 1.8× usual Si Sa Ket, 30 November: 25.7 µg/m³, 2.3× usual Si Sa Ket, 1 December: 26.2 µg/m³, 2.3× usual Si Sa Ket, 2 December: 13.4 µg/m³, 1.2× usual Si Sa Ket, 3 December: 11.5 µg/m³, 1.0× usual Si Sa Ket, 4 December: 10.4 µg/m³, 0.9× usual Si Sa Ket, 5 December: 8.1 µg/m³, 0.7× usual Si Sa Ket, 6 December: 6.2 µg/m³, 0.6× usual Khan Na Yao Khan Na Yao, 27 November: 37.8 µg/m³, 1.3× usual Khan Na Yao, 28 November: 38.1 µg/m³, 1.3× usual Khan Na Yao, 29 November: 38.7 µg/m³, 1.3× usual Khan Na Yao, 30 November: 40.4 µg/m³, 1.4× usual Khan Na Yao, 1 December: 45.7 µg/m³, 1.6× usual Khan Na Yao, 2 December: 58.7 µg/m³, 2.0× usual Khan Na Yao, 3 December: 53.4 µg/m³, 1.9× usual Khan Na Yao, 4 December: 39.3 µg/m³, 1.4× usual Khan Na Yao, 5 December: 20.2 µg/m³, 0.7× usual Khan Na Yao, 6 December: 31.5 µg/m³, 1.1× usual Phra Pradaeng Phra Pradaeng, 27 November: 33.6 µg/m³, 1.3× usual Phra Pradaeng, 28 November: 32.9 µg/m³, 1.3× usual Phra Pradaeng, 29 November: 35.7 µg/m³, 1.4× usual Phra Pradaeng, 30 November: 43.4 µg/m³, 1.7× usual Phra Pradaeng, 1 December: 46.5 µg/m³, 1.8× usual Phra Pradaeng, 2 December: 52.9 µg/m³, 2.0× usual Phra Pradaeng, 3 December: 49.2 µg/m³, 1.9× usual Phra Pradaeng, 4 December: 38.7 µg/m³, 1.5× usual Phra Pradaeng, 5 December: 22.4 µg/m³, 0.9× usual Phra Pradaeng, 6 December: 27.1 µg/m³, 1.0× usual Samut Prakan Samut Prakan, 27 November: 30.2 µg/m³, 1.4× usual Samut Prakan, 28 November: 27.8 µg/m³, 1.3× usual Samut Prakan, 29 November: 29.5 µg/m³, 1.3× usual Samut Prakan, 30 November: 38.3 µg/m³, 1.7× usual Samut Prakan, 1 December: 39.8 µg/m³, 1.8× usual Samut Prakan, 2 December: 45.3 µg/m³, 2.1× usual Samut Prakan, 3 December: 40.3 µg/m³, 1.8× usual Samut Prakan, 4 December: 28.0 µg/m³, 1.3× usual Samut Prakan, 5 December: 12.5 µg/m³, 0.6× usual Samut Prakan, 6 December: 17.1 µg/m³, 0.8× usual Ban Chang Ban Chang, 27 November: 17.5 µg/m³, 1.1× usual Ban Chang, 28 November: 14.3 µg/m³, 0.9× usual Ban Chang, 29 November: 17.4 µg/m³, 1.1× usual Ban Chang, 30 November: 30.7 µg/m³, 2.0× usual Ban Chang, 1 December: 36.8 µg/m³, 2.3× usual Ban Chang, 2 December: 46.2 µg/m³, 2.9× usual Ban Chang, 3 December: 44.0 µg/m³, 2.8× usual Ban Chang, 4 December: 36.7 µg/m³, 2.3× usual Ban Chang, 5 December: 9.6 µg/m³, 0.6× usual Ban Chang, 6 December: 9.2 µg/m³, 0.6× usual Rayong Rayong, 27 November: 16.8 µg/m³, 1.0× usual Rayong, 28 November: 16.4 µg/m³, 1.0× usual Rayong, 29 November: 22.1 µg/m³, 1.3× usual Rayong, 30 November: 32.2 µg/m³, 1.9× usual Rayong, 1 December: 32.0 µg/m³, 1.9× usual Rayong, 2 December: 33.6 µg/m³, 2.0× usual Rayong, 3 December: 39.6 µg/m³, 2.3× usual Rayong, 4 December: 27.2 µg/m³, 1.6× usual Rayong, 5 December: 11.4 µg/m³, 0.7× usual Rayong, 6 December: 11.8 µg/m³, 0.7× usual Lop Buri Lop Buri, 27 November: 24.8 µg/m³, 1.6× usual Lop Buri, 28 November: 23.3 µg/m³, 1.5× usual Lop Buri, 29 November: 27.7 µg/m³, 1.8× usual Lop Buri, 30 November: 31.0 µg/m³, 2.1× usual Lop Buri, 1 December: 36.2 µg/m³, 2.4× usual Lop Buri, 2 December: 35.2 µg/m³, 2.3× usual Lop Buri, 3 December: 33.5 µg/m³, 2.2× usual Lop Buri, 4 December: 20.1 µg/m³, 1.3× usual 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 2 December 15.7 2.9× Chumphon Chumphon, Thailand 3 1 December 16.7 2.6× Sakon Nakhon Sakon Nakhon, Thailand 1 29 November 13.2 2.5× Surin Surin, Thailand 1 30 November 14.8 2.5× Lop Buri Lopburi, Thailand 1 1 December 15.1 2.4× Phichit Phichit, Thailand 2 1 December 17.0 2.3× Mueang Nonthaburi Nonthaburi, Thailand 3 2 December 27.3 2.3× Si Sa Ket Si Sa Ket, Thailand 1 1 December 11.2 2.3× Mukdahan Mukdahan, Thailand 1 29 November 13.4 2.3× Rayong Rayong, Thailand 1 3 December 17.2 2.3× Bang Bo District Samut Prakan, Thailand 3 3 December 25.8 2.3× Chiang Rai Chiang Rai, Thailand 1 1 December 16.8 2.2× Phetchaburi Phetchaburi, Thailand 3 2 December 21.8 2.2× Nong Bua Lamphu Nong Bua Lamphu, Thailand 1 30 November 13.0 2.1× Kalasin Kalasin, Thailand 2 1 December 24.9 2.1× Nakhon Nayok Nakhon Nayok, Thailand 1 1 December 15.1 2.1× Samut Prakan Samut Prakan, Thailand 1 2 December 22.0 2.1× Nong Chok Bangkok, Thailand 2 2 December 21.8 2.0× Khan Na Yao Bangkok, Thailand 1 2 December 28.8 2.0× Phra Pradaeng Samut Prakan, Thailand 1 2 December 26.1 2.0× Phayao Phayao, Thailand 1 1 December 15.9 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 and Laos
Number 3 of 7 episodes in Thailand and Laos since our records began, by cities reached.
Bars: cities reached; colour: the level of the episode's highest daily reading.
Use this page SmogRank, Northern Thailand, 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-northern-thailand (accessed 2 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.
