SmogRank / Episodes / Thailand

Northern 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/m³Sukhothai, 4 March: 62.1 µg/m³Sukhothai, 5 March: no readingSukhothai, 6 March: 124.0 µg/m³, 3.8× its usual 32.9Sukhothai, 7 March: 128.0 µg/m³, 3.8× its usual 33.7Sukhothai, 8 March: no readingSukhothai, 9 March: no readingSukhothai, 10 March: no readingLampangLampang, 3 March: 61.3 µg/m³Lampang, 4 March: 55.5 µg/m³Lampang, 5 March: no readingLampang, 6 March: 105.0 µg/m³, 2.1× its usual 49.8Lampang, 7 March: 178.0 µg/m³, 3.6× its usual 50.0Lampang, 8 March: no readingLampang, 9 March: no readingLampang, 10 March: no readingPhraePhrae, 3 March: 57.9 µg/m³Phrae, 4 March: 54.9 µg/m³Phrae, 5 March: no readingPhrae, 6 March: 101.0 µg/m³, 2.5× its usual 41.0Phrae, 7 March: 125.0 µg/m³, 3.0× its usual 41.3Phrae, 8 March: no readingPhrae, 9 March: no readingPhrae, 10 March: no readingMae SaiMae Sai, 3 March: 74.9 µg/m³Mae Sai, 4 March: 81.0 µg/m³Mae Sai, 5 March: no readingMae Sai, 6 March: 98.1 µg/m³, 2.2× its usual 45.0Mae Sai, 7 March: 114.0 µg/m³, 2.5× its usual 46.4Mae Sai, 8 March: no readingMae Sai, 9 March: no readingMae Sai, 10 March: no readingLoeiLoei, 3 March: 45.0 µg/m³Loei, 4 March: 68.5 µg/m³Loei, 5 March: no readingLoei, 6 March: 96.3 µg/m³, 2.7× its usual 35.9Loei, 7 March: 130.0 µg/m³, 3.6× its usual 36.0Loei, 8 March: no readingLoei, 9 March: no readingLoei, 10 March: no readingBan HouakhouaBan Houakhoua, 3 March: 55.0 µg/m³Ban Houakhoua, 4 March: 49.7 µg/m³Ban Houakhoua, 5 March: no readingBan Houakhoua, 6 March: 79.2 µg/m³, 2.7× its usual 29.1Ban 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/m³Chiang Mai, 4 March: 34.8 µg/m³Chiang Mai, 5 March: no readingChiang Mai, 6 March: 68.7 µg/m³, 2.1× its usual 32.5Chiang Mai, 7 March: 95.5 µg/m³, 2.8× its usual 33.7Chiang Mai, 8 March: no readingChiang Mai, 9 March: no readingChiang Mai, 10 March: no readingUdon ThaniUdon Thani, 3 March: 20.5 µg/m³Udon Thani, 4 March: 36.5 µg/m³Udon Thani, 5 March: no readingUdon Thani, 6 March: 65.5 µg/m³, 2.2× its usual 29.5Udon Thani, 7 March: 82.9 µg/m³, 2.8× its usual 29.5Udon Thani, 8 March: no readingUdon Thani, 9 March: no readingUdon Thani, 10 March: no readingSakon NakhonSakon Nakhon, 3 March: 11.9 µg/m³Sakon Nakhon, 4 March: 35.8 µg/m³Sakon Nakhon, 5 March: no readingSakon Nakhon, 6 March: 58.1 µg/m³, 2.5× its usual 23.4Sakon Nakhon, 7 March: 71.8 µg/m³, 2.8× its usual 25.5Sakon Nakhon, 8 March: no readingSakon Nakhon, 9 March: no readingSakon Nakhon, 10 March: no readingLamphunLamphun, 3 March: 62.7 µg/m³Lamphun, 4 March: 41.8 µg/m³Lamphun, 5 March: no readingLamphun, 6 March: 72.2 µg/m³Lamphun, 7 March: 110.0 µg/m³, 2.3× its usual 48.2Lamphun, 8 March: no readingLamphun, 9 March: no readingLamphun, 10 March: no readingUttaraditUttaradit, 3 March: 50.0 µg/m³Uttaradit, 4 March: 46.8 µg/m³Uttaradit, 5 March: no readingUttaradit, 6 March: 56.5 µg/m³Uttaradit, 7 March: 83.6 µg/m³, 2.0× its usual 41.4Uttaradit, 8 March: no readingUttaradit, 9 March: no readingUttaradit, 10 March: no readingPakxanPakxan, 3 March: 20.1 µg/m³Pakxan, 4 March: 31.8 µg/m³Pakxan, 5 March: no readingPakxan, 6 March: 53.9 µg/m³Pakxan, 7 March: 80.8 µg/m³, 2.6× its usual 30.7Pakxan, 8 March: no readingPakxan, 9 March: no readingPakxan, 10 March: no readingMukdahanMukdahan, 3 March: 26.9 µg/m³Mukdahan, 4 March: 58.3 µg/m³Mukdahan, 5 March: no readingMukdahan, 6 March: 60.2 µg/m³Mukdahan, 7 March: 75.6 µg/m³, 2.1× its usual 36.4Mukdahan, 8 March: no readingMukdahan, 9 March: no readingMukdahan, 10 March: no readingNong Bua LamphuNong Bua Lamphu, 3 March: 22.0 µg/m³Nong Bua Lamphu, 4 March: 36.1 µg/m³Nong Bua Lamphu, 5 March: no readingNong Bua Lamphu, 6 March: 52.0 µg/m³Nong Bua Lamphu, 7 March: 67.3 µg/m³, 2.2× its usual 30.8Nong 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×
LampangLampang, Thailand2 178.07 March50.03.6×
LoeiLoei, Thailand2 130.07 March36.03.6×
PhraePhrae, Thailand2 125.07 March41.33.0×
Chiang MaiChiang Mai, Thailand2 95.57 March33.72.8×
Udon ThaniUdon Thani, Thailand2 82.97 March29.52.8×
Sakon NakhonSakon Nakhon, Thailand2 71.87 March25.52.8×
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, 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 14 of 23 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 23.

Use this page

SmogRank, Northern 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-northern-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.