SmogRank / Episodes / Thailand

Northern Thailand, February 2025

For 3 days, from 1 to 3 February 2025, 9 cities in Thailand had PM2.5 at least twice their usual for the time of year. The worst reading was Phetchaburi, Phetchaburi, Thailand: 80.1 µg/m³ on 1 February, about 2.0× its usual 39.6.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached9in 1 country
Days31 to 3 February 2025
Worst day1 February7 cities counted
Furthest above usual3.2×Si Sa Ket

Day by day

1 February 7 cities at twice their usual or more
Nakhon RatchasimaAranyaprathetSi Maha PhotChaiyaphumSurinPrachin BuriNakhon NayokSaraburiLop BuriNong ChokNakhon LuangMaha SarakhamKhon KaenPhra Nakhon Si AyutthayaKhlong Sam WaKhlong LuangLat KrabangSai MaiRoi EtKhan Na YaoBang Bo DistrictSaphan SungBueng KumBan Khlong PrawetSing BuriBang KapiLak SiBang NaMueang NonthaburiPhetchabunSamut PrakanKalasinBangkokPhra PradaengChanthaburiLaem ChabangSuphan BuriNong KhaemBan Samae DamChai NatRayongSamut SakhonBan ChangNakhon SawanNakhon PathomBan PhaeoAmnat CharoenUbon RatchathaniPhichitUdon ThaniRatchaburiLoeiKanchanaburiHua HinKamphaeng PhetSukhothaiMae SotMukdahanBan Talat BuengTratPhetchaburiNong Bua LamphuSakon NakhonBuri RamYasothonSi Sa Ket
29 Jan30311 Feb23456
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

PhetchaburiPhetchaburi, 29 January: no readingPhetchaburi, 30 January: no readingPhetchaburi, 31 January: 77.0 µg/m³Phetchaburi, 1 February: 80.1 µg/m³, 2.0× its usual 39.6Phetchaburi, 2 February: 73.1 µg/m³Phetchaburi, 3 February: 65.9 µg/m³Phetchaburi, 4 February: 55.8 µg/m³Phetchaburi, 5 February: 69.9 µg/m³Phetchaburi, 6 February: 42.0 µg/m³Si Sa KetSi Sa Ket, 29 January: no readingSi Sa Ket, 30 January: no readingSi Sa Ket, 31 January: no readingSi Sa Ket, 1 February: 75.1 µg/m³, 3.2× its usual 23.7Si Sa Ket, 2 February: 73.5 µg/m³, 3.0× its usual 24.3Si Sa Ket, 3 February: 72.2 µg/m³, 2.9× its usual 24.7Si Sa Ket, 4 February: 32.6 µg/m³Si Sa Ket, 5 February: 9.6 µg/m³Si Sa Ket, 6 February: 30.9 µg/m³TratTrat, 29 January: no readingTrat, 30 January: no readingTrat, 31 January: 72.4 µg/m³Trat, 1 February: 69.1 µg/m³, 2.0× its usual 34.0Trat, 2 February: 77.0 µg/m³Trat, 3 February: 57.3 µg/m³Trat, 4 February: 45.0 µg/m³Trat, 5 February: 45.9 µg/m³Trat, 6 February: 42.1 µg/m³Ban Talat BuengBan Talat Bueng, 29 January: no readingBan Talat Bueng, 30 January: no readingBan Talat Bueng, 31 January: 63.7 µg/m³Ban Talat Bueng, 1 February: 66.4 µg/m³, 2.0× its usual 33.2Ban Talat Bueng, 2 February: 59.9 µg/m³Ban Talat Bueng, 3 February: 55.4 µg/m³Ban Talat Bueng, 4 February: 47.1 µg/m³Ban Talat Bueng, 5 February: 52.4 µg/m³Ban Talat Bueng, 6 February: 46.4 µg/m³YasothonYasothon, 29 January: no readingYasothon, 30 January: no readingYasothon, 31 January: 59.3 µg/m³Yasothon, 1 February: 66.2 µg/m³, 2.3× its usual 28.4Yasothon, 2 February: 70.6 µg/m³, 2.4× its usual 29.4Yasothon, 3 February: 63.6 µg/m³, 2.0× its usual 31.3Yasothon, 4 February: 32.8 µg/m³Yasothon, 5 February: 28.9 µg/m³Yasothon, 6 February: 47.7 µg/m³Buri RamBuri Ram, 29 January: no readingBuri Ram, 30 January: no readingBuri Ram, 31 January: 32.4 µg/m³Buri Ram, 1 February: 53.9 µg/m³, 2.1× its usual 25.8Buri Ram, 2 February: 51.6 µg/m³Buri Ram, 3 February: 64.0 µg/m³, 2.4× its usual 26.8Buri Ram, 4 February: 37.7 µg/m³Buri Ram, 5 February: 25.5 µg/m³Buri Ram, 6 February: 51.8 µg/m³Sakon NakhonSakon Nakhon, 29 January: no readingSakon Nakhon, 30 January: no readingSakon Nakhon, 31 January: 32.2 µg/m³Sakon Nakhon, 1 February: 42.1 µg/m³, 2.1× its usual 19.6Sakon Nakhon, 2 February: 48.8 µg/m³, 2.4× its usual 20.1Sakon Nakhon, 3 February: 43.6 µg/m³, 2.1× its usual 20.3Sakon Nakhon, 4 February: 14.9 µg/m³Sakon Nakhon, 5 February: 9.9 µg/m³Sakon Nakhon, 6 February: 23.2 µg/m³MukdahanMukdahan, 29 January: no readingMukdahan, 30 January: no readingMukdahan, 31 January: 50.1 µg/m³Mukdahan, 1 February: 51.4 µg/m³Mukdahan, 2 February: 56.2 µg/m³, 2.0× its usual 27.7Mukdahan, 3 February: 48.8 µg/m³Mukdahan, 4 February: 19.0 µg/m³Mukdahan, 5 February: 17.9 µg/m³Mukdahan, 6 February: 38.9 µg/m³Nong Bua LamphuNong Bua Lamphu, 29 January: no readingNong Bua Lamphu, 30 January: no readingNong Bua Lamphu, 31 January: 37.1 µg/m³Nong Bua Lamphu, 1 February: 45.7 µg/m³Nong Bua Lamphu, 2 February: 49.8 µg/m³Nong Bua Lamphu, 3 February: 61.3 µg/m³, 2.1× its usual 29.6Nong Bua Lamphu, 4 February: 30.3 µg/m³Nong Bua Lamphu, 5 February: no readingNong Bua Lamphu, 6 February: 36.3 µg/m³29 Jan30311 Feb23456
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.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

Every city it reached

CityDaysHighestUsualAbove usual
Si Sa KetSi Sa Ket, Thailand3 75.11 February23.73.2×
YasothonYasothon, Thailand3 70.62 February29.42.4×
Buri RamBuriram, Thailand2 64.03 February26.82.4×
Sakon NakhonSakon Nakhon, Thailand3 48.82 February20.12.4×
Nong Bua LamphuNong Bua Lamphu, Thailand1 61.33 February29.62.1×
PhetchaburiPhetchaburi, Thailand1 80.11 February39.62.0×
TratTrat, Thailand1 69.11 February34.02.0×
Ban Talat BuengChon Buri, Thailand1 66.41 February33.22.0×
MukdahanMukdahan, Thailand1 56.22 February27.72.0×

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

Number 16 of 23 episodes in Thailand since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 23.

Use this page

SmogRank, Northern Thailand, February 2025: 9 cities with PM2.5 at twice their usual or more, 1 to 3 February 2025, smogrank.com/episodes/2025-02-northern-thailand (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.