SmogRank / Episodes / Thailand

Bangkok and Surin, Thailand, May 2024

For 1 day, on 15 May 2024, 8 cities in Thailand had PM2.5 at least twice their usual for the time of year. The worst reading was Nong Khaem, Bangkok, Thailand: 46.5 µg/m³ on 15 May, about 2.7× its usual 17.3.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached8in 1 country
Days115 May 2024
Worst day15 May8 cities counted
Furthest above usual3.1×Surin

Day by day

15 May 8 cities at twice their usual or more
Si Maha PhotAranyaprathetNakhon NayokNakhon RatchasimaNong ChokSaraburiLat KrabangBang Bo DistrictKhlong Sam WaKhan Na YaoSaphan SungBan Khlong PrawetKhlong LuangBang KapiBan Talat BuengBang NaSamut PrakanChanthaburiPhra Nakhon Si AyutthayaPhra PradaengRayongLop BuriBan ChangBuri RamSamut SakhonSing BuriChaiyaphumTratSuphan BuriNakhon PathomRatchaburiPhetchaburiChai NatKanchanaburiHua HinNakhon SawanPhetchabunSi Sa KetRoi EtYasothonKalasinUbon RatchathaniAmnat CharoenBangkokSai MaiLak SiLaem ChabangMueang NonthaburiBan Samae DamNong KhaemSurin
12 May131415161718
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

Nong KhaemNong Khaem, 12 May: 35.2 µg/m³, 2.0× usualNong Khaem, 13 May: 26.9 µg/m³, 1.6× usualNong Khaem, 14 May: 26.5 µg/m³, 1.5× usualNong Khaem, 15 May: 46.5 µg/m³, 2.7× usualNong Khaem, 16 May: 26.8 µg/m³, 1.5× usualNong Khaem, 17 May: no readingNong Khaem, 18 May: 17.9 µg/m³, 1.0× usualLaem ChabangLaem Chabang, 12 May: 21.8 µg/m³, 1.6× usualLaem Chabang, 13 May: 29.1 µg/m³, 2.1× usualLaem Chabang, 14 May: 17.3 µg/m³, 1.3× usualLaem Chabang, 15 May: 35.7 µg/m³, 2.6× usualLaem Chabang, 16 May: 34.6 µg/m³, 2.5× usualLaem Chabang, 17 May: 20.3 µg/m³, 1.5× usualLaem Chabang, 18 May: 17.5 µg/m³, 1.3× usualBan Samae DamBan Samae Dam, 12 May: 30.4 µg/m³, 1.8× usualBan Samae Dam, 13 May: 28.0 µg/m³, 1.6× usualBan Samae Dam, 14 May: 25.0 µg/m³, 1.4× usualBan Samae Dam, 15 May: 46.0 µg/m³, 2.7× usualBan Samae Dam, 16 May: 27.3 µg/m³, 1.6× usualBan Samae Dam, 17 May: 21.4 µg/m³, 1.2× usualBan Samae Dam, 18 May: 17.5 µg/m³, 1.0× usualMueang NonthaburiMueang Nonthaburi, 12 May: 25.7 µg/m³, 1.9× usualMueang Nonthaburi, 13 May: 23.4 µg/m³, 1.7× usualMueang Nonthaburi, 14 May: 21.4 µg/m³, 1.6× usualMueang Nonthaburi, 15 May: 36.0 µg/m³, 2.6× usualMueang Nonthaburi, 16 May: 28.4 µg/m³, 2.1× usualMueang Nonthaburi, 17 May: 16.6 µg/m³, 1.2× usualMueang Nonthaburi, 18 May: 15.6 µg/m³, 1.1× usualLak SiLak Si, 12 May: 25.4 µg/m³, 1.5× usualLak Si, 13 May: 26.3 µg/m³, 1.6× usualLak Si, 14 May: 23.2 µg/m³, 1.4× usualLak Si, 15 May: 35.0 µg/m³, 2.1× usualLak Si, 16 May: 29.5 µg/m³, 1.8× usualLak Si, 17 May: 19.3 µg/m³, 1.2× usualLak Si, 18 May: 17.4 µg/m³, 1.0× usualBangkokBangkok, 12 May: 26.4 µg/m³, 1.6× usualBangkok, 13 May: 24.0 µg/m³, 1.4× usualBangkok, 14 May: 21.1 µg/m³, 1.3× usualBangkok, 15 May: 33.5 µg/m³, 2.0× usualBangkok, 16 May: 26.8 µg/m³, 1.6× usualBangkok, 17 May: 18.0 µg/m³, 1.1× usualBangkok, 18 May: 15.4 µg/m³, 0.9× usualSurinSurin, 12 May: 21.3 µg/m³, 2.1× usualSurin, 13 May: 19.1 µg/m³, 1.9× usualSurin, 14 May: 16.6 µg/m³, 1.6× usualSurin, 15 May: 32.1 µg/m³, 3.1× usualSurin, 16 May: 23.8 µg/m³, 2.3× usualSurin, 17 May: 28.8 µg/m³, 2.8× usualSurin, 18 May: 16.6 µg/m³, 1.6× usualSai MaiSai Mai, 12 May: 22.5 µg/m³, 1.6× usualSai Mai, 13 May: 22.5 µg/m³, 1.6× usualSai Mai, 14 May: 20.5 µg/m³, 1.4× usualSai Mai, 15 May: 31.0 µg/m³, 2.1× usualSai Mai, 16 May: 26.1 µg/m³, 1.8× usualSai Mai, 17 May: 16.3 µg/m³, 1.1× usualSai Mai, 18 May: 14.0 µg/m³, 1.0× usual12 May131415161718
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
SurinSurin, Thailand1 32.115 May10.33.1×
Nong KhaemBangkok, Thailand1 46.515 May17.32.7×
Ban Samae DamBangkok, Thailand1 46.015 May17.32.7×
Mueang NonthaburiNonthaburi, Thailand1 36.015 May13.82.6×
Laem ChabangChon Buri, Thailand1 35.715 May13.82.6×
Sai MaiBangkok, Thailand1 31.015 May14.52.1×
Lak SiBangkok, Thailand1 35.015 May16.72.1×
BangkokBangkok, Thailand1 33.515 May16.72.0×

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 23 of 24 episodes in Thailand since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 24.

Use this page

SmogRank, Bangkok and Surin, Thailand, May 2024: 8 cities with PM2.5 at twice their usual or more, 15 May 2024, smogrank.com/episodes/2024-05-bangkok-and-surin-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.