SmogRank / Episodes / Thailand

North-western Thailand and Laos, March 2024

For 2 days, from 6 to 7 March 2024, 14 cities in Thailand and Laos had PM2.5 at least twice their usual for the time of year. The worst reading was Lampang, Lampang, Thailand: 178.0 µg/m³ on 7 March, about 3.6× its usual 50.0.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached14in 2 countries
Days26 to 7 March 2024
Worst day7 March13 cities counted
Furthest above usual3.8×Sukhothai

Day by day

7 March 13 cities at twice their usual or more
NanPhayaoPhetchabunKhon KaenChiang RaiPhichitKalasinRoi EtKamphaeng PhetMae SotUttaraditMukdahanNong Bua LamphuLamphunMae SaiPakxanBan HouakhouaSakon NakhonUdon ThaniChiang MaiPhraeLoeiLampangSukhothai
3 Mar45678910
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

SukhothaiSukhothai, 3 March: 64.2 µg/m³, 1.9× usualSukhothai, 4 March: 62.1 µg/m³, 1.8× usualSukhothai, 5 March: no readingSukhothai, 6 March: 124.0 µg/m³, 3.7× usualSukhothai, 7 March: 128.0 µg/m³, 3.8× usualSukhothai, 8 March: no readingSukhothai, 9 March: no readingSukhothai, 10 March: no readingLampangLampang, 3 March: 61.3 µg/m³, 1.2× usualLampang, 4 March: 55.5 µg/m³, 1.1× usualLampang, 5 March: no readingLampang, 6 March: 105.0 µg/m³, 2.1× usualLampang, 7 March: 178.0 µg/m³, 3.6× usualLampang, 8 March: no readingLampang, 9 March: no readingLampang, 10 March: no readingPhraePhrae, 3 March: 57.9 µg/m³, 1.4× usualPhrae, 4 March: 54.9 µg/m³, 1.3× usualPhrae, 5 March: no readingPhrae, 6 March: 101.0 µg/m³, 2.4× usualPhrae, 7 March: 125.0 µg/m³, 3.0× usualPhrae, 8 March: no readingPhrae, 9 March: no readingPhrae, 10 March: no readingMae SaiMae Sai, 3 March: 74.9 µg/m³, 1.6× usualMae Sai, 4 March: 81.0 µg/m³, 1.7× usualMae Sai, 5 March: no readingMae Sai, 6 March: 98.1 µg/m³, 2.1× usualMae Sai, 7 March: 114.0 µg/m³, 2.5× usualMae Sai, 8 March: no readingMae Sai, 9 March: no readingMae Sai, 10 March: no readingLoeiLoei, 3 March: 45.0 µg/m³, 1.3× usualLoei, 4 March: 68.5 µg/m³, 1.9× usualLoei, 5 March: no readingLoei, 6 March: 96.3 µg/m³, 2.7× usualLoei, 7 March: 130.0 µg/m³, 3.6× usualLoei, 8 March: no readingLoei, 9 March: no readingLoei, 10 March: no readingBan HouakhouaBan Houakhoua, 3 March: 55.0 µg/m³, 1.9× usualBan Houakhoua, 4 March: 49.7 µg/m³, 1.7× usualBan Houakhoua, 5 March: no readingBan Houakhoua, 6 March: 79.2 µg/m³, 2.7× usualBan Houakhoua, 7 March: no readingBan Houakhoua, 8 March: no readingBan Houakhoua, 9 March: no readingBan Houakhoua, 10 March: no readingChiang MaiChiang Mai, 3 March: 41.9 µg/m³, 1.2× usualChiang Mai, 4 March: 34.8 µg/m³, 1.0× usualChiang Mai, 5 March: no readingChiang Mai, 6 March: 68.7 µg/m³, 2.0× usualChiang Mai, 7 March: 95.5 µg/m³, 2.8× usualChiang Mai, 8 March: no readingChiang Mai, 9 March: no readingChiang Mai, 10 March: no readingUdon ThaniUdon Thani, 3 March: 20.5 µg/m³, 0.7× usualUdon Thani, 4 March: 36.5 µg/m³, 1.2× usualUdon Thani, 5 March: no readingUdon Thani, 6 March: 65.5 µg/m³, 2.2× usualUdon Thani, 7 March: 82.9 µg/m³, 2.8× usualUdon Thani, 8 March: no readingUdon Thani, 9 March: no readingUdon Thani, 10 March: no readingSakon NakhonSakon Nakhon, 3 March: 11.9 µg/m³, 0.5× usualSakon Nakhon, 4 March: 35.8 µg/m³, 1.4× usualSakon Nakhon, 5 March: no readingSakon Nakhon, 6 March: 58.1 µg/m³, 2.3× usualSakon Nakhon, 7 March: 71.8 µg/m³, 2.8× usualSakon Nakhon, 8 March: no readingSakon Nakhon, 9 March: no readingSakon Nakhon, 10 March: no readingLamphunLamphun, 3 March: 62.7 µg/m³, 1.3× usualLamphun, 4 March: 41.8 µg/m³, 0.9× usualLamphun, 5 March: no readingLamphun, 6 March: 72.2 µg/m³, 1.5× usualLamphun, 7 March: 110.0 µg/m³, 2.3× usualLamphun, 8 March: no readingLamphun, 9 March: no readingLamphun, 10 March: no readingUttaraditUttaradit, 3 March: 50.0 µg/m³, 1.2× usualUttaradit, 4 March: 46.8 µg/m³, 1.1× usualUttaradit, 5 March: no readingUttaradit, 6 March: 56.5 µg/m³, 1.4× usualUttaradit, 7 March: 83.6 µg/m³, 2.0× usualUttaradit, 8 March: no readingUttaradit, 9 March: no readingUttaradit, 10 March: no readingPakxanPakxan, 3 March: 20.1 µg/m³, 0.7× usualPakxan, 4 March: 31.8 µg/m³, 1.0× usualPakxan, 5 March: no readingPakxan, 6 March: 53.9 µg/m³, 1.8× usualPakxan, 7 March: 80.8 µg/m³, 2.6× usualPakxan, 8 March: no readingPakxan, 9 March: no readingPakxan, 10 March: no readingMukdahanMukdahan, 3 March: 26.9 µg/m³, 0.7× usualMukdahan, 4 March: 58.3 µg/m³, 1.6× usualMukdahan, 5 March: no readingMukdahan, 6 March: 60.2 µg/m³, 1.7× usualMukdahan, 7 March: 75.6 µg/m³, 2.1× usualMukdahan, 8 March: no readingMukdahan, 9 March: no readingMukdahan, 10 March: no readingNong Bua LamphuNong Bua Lamphu, 3 March: 22.0 µg/m³, 0.7× usualNong Bua Lamphu, 4 March: 36.1 µg/m³, 1.2× usualNong Bua Lamphu, 5 March: no readingNong Bua Lamphu, 6 March: 52.0 µg/m³, 1.7× usualNong Bua Lamphu, 7 March: 67.3 µg/m³, 2.2× usualNong Bua Lamphu, 8 March: no readingNong Bua Lamphu, 9 March: no readingNong Bua Lamphu, 10 March: no reading3 Mar45678910
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
SukhothaiSukhothai, Thailand2 128.07 March33.73.8×
LoeiLoei, Thailand2 130.07 March36.03.6×
LampangLampang, Thailand2 178.07 March50.03.6×
PhraePhrae, Thailand2 125.07 March41.33.0×
Chiang MaiChiang Mai, Thailand2 95.57 March33.72.8×
Sakon NakhonSakon Nakhon, Thailand2 71.87 March25.52.8×
Udon ThaniUdon Thani, Thailand2 82.97 March29.52.8×
Ban HouakhouaBokeo, Laos1 79.26 March29.12.7×
PakxanBolikhamsai, Laos1 80.87 March30.72.6×
Mae SaiChiang Rai, Thailand2 114.07 March46.42.5×
LamphunLamphun, Thailand1 110.07 March48.22.3×
Nong Bua LamphuNong Bua Lamphu, Thailand1 67.37 March30.82.2×
MukdahanMukdahan, Thailand1 75.67 March36.42.1×
UttaraditUttaradit, Thailand1 83.67 March41.42.0×

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 14 of 24 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. All 24.

Use this page

SmogRank, North-western Thailand and Laos, March 2024: 14 cities with PM2.5 at twice their usual or more, 6 to 7 March 2024, smogrank.com/episodes/2024-03-north-western-thailand-and-laos (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.