24 – 30 Sep 2025 · Thailand · Wednesday to Tuesday, UTC+7

Thailand weekly air quality

Modelled US AQI · 8 cities · CAMS via Open-Meteo

37Weekly mean modelled AQI · Good

Mean PM2.5: 6.9 µg/m³. Both means cover the selected cities hour by hour. They are not a national average or Thailand’s official index.

-7.3 AQI compared with the previous week’s mean of 44.3.

Highest hourly estimate: 63 in Chiang Mai · 26 Sept, 18:00 GMT+7.

1344 of 1344 city-hours have a modelled AQI. These are estimates for roughly 45 km model grid cells, not monitoring-station measurements. How this report is made

Daily modelled US AQI

Day	Mean AQI	Low–high	Mean PM2.5 (µg/m³)	City-hours
Wed, 24 Sep	33.4Good	16–50	6.1	192 / 192
Thu, 25 Sep	37Good	17–59	6.9	192 / 192
Fri, 26 Sep	35.6Good	16–63	7	192 / 192
Sat, 27 Sep	39.2Good	12–61	7.4	192 / 192
Sun, 28 Sep	41.4Good	13–59	8.2	192 / 192
Mon, 29 Sep	39.4Good	17–60	6.9	192 / 192
Tue, 30 Sep	33Good	16–55	5.7	192 / 192

Hourly means (UTC+7)

Each cell averages the selected cities’ modelled AQI for that hour.

Day	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23
Wed	37	36	35	34	34	33	32	32	32	32	32	32	32	32	32	33	33	34	34	34	35	35	35	34
Thu	35	35	35	36	36	37	37	37	37	37	37	37	37	37	37	37	38	39	39	39	39	38	38	37
Fri	37	36	36	35	35	35	34	34	34	34	34	34	35	35	35	36	37	37	38	37	37	37	37	37
Sat	37	37	38	38	39	39	39	39	39	40	40	39	39	39	39	40	41	41	41	40	39	39	39	39
Sun	39	39	40	40	40	40	40	40	40	41	41	41	42	42	42	43	44	43	44	44	43	43	42	41
Mon	41	41	40	40	40	40	40	40	40	40	40	39	39	39	39	39	39	39	39	38	39	38	38	38
Tue	37	37	36	36	35	34	34	33	32	32	31	31	31	30	31	31	32	33	34	33	33	33	33	33

Cities by modelled US AQI

Sorted by weekly mean. Each city is a single model grid cell near its centre.

City	Mean AQI	Peak AQI	Mean PM2.5 (µg/m³)	Hours
Chiang Mai	54.3Moderate	63	11.3	168 / 168
Bangkok	40.3Good	60	8.1	168 / 168
Nakhon Ratchasima	39.8Good	57	7	168 / 168
Khon Kaen	37.6Good	49	6.6	168 / 168
Chiang Rai	37.5Good	57	6.8	168 / 168
Phuket	34.3Good	48	6.3	168 / 168
Hat Yai	33.1Good	47	6.3	168 / 168
Pattaya	19Good	29	2.7	168 / 168

City-hours by category

Good: 1086

Moderate: 258

Unhealthy for Sensitive Groups: 0

Unhealthy: 0

Very Unhealthy: 0

Hazardous: 0

US AQI scale
AQI	Category
0–50	Good
51–100	Moderate
101–150	Unhealthy for Sensitive Groups
151–200	Unhealthy
201–300	Very Unhealthy
301+	Hazardous

How this report is made

Open-Meteo provides hourly estimates from the Copernicus Atmosphere Monitoring Service (CAMS) global model at roughly 45 km resolution. We use the grid cell nearest each city’s centre. Nearby places may share a cell, and local pollution can differ.

The AQI is the provider’s modelled US AQI across pollutants, one value per city per hour. Weekly, daily and hourly means average those values across the selected cities. PM2.5 is a concentration in µg/m³. These figures use a different basis from the measured PM2.5-derived AQI in the Malaysia and Singapore reports.

Days and hours use UTC+7. The report includes past model hours only, never forecasts. The previous-week comparison appears only when at least 90% of that week’s city-hours are available.

For official local readings and advice, visit Pollution Control Department · Air4Thai. Air-quality data: Open-Meteo and CAMS, licensed under CC BY 4.0. Haze Monitor is independent of these providers and local authorities.

Day	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23
Wed	37	36	35	34	34	33	32	32	32	32	32	32	32	32	32	33	33	34	34	34	35	35	35	34
Thu	35	35	35	36	36	37	37	37	37	37	37	37	37	37	37	37	38	39	39	39	39	38	38	37
Fri	37	36	36	35	35	35	34	34	34	34	34	34	35	35	35	36	37	37	38	37	37	37	37	37
Sat	37	37	38	38	39	39	39	39	39	40	40	39	39	39	39	40	41	41	41	40	39	39	39	39
Sun	39	39	40	40	40	40	40	40	40	41	41	41	42	42	42	43	44	43	44	44	43	43	42	41
Mon	41	41	40	40	40	40	40	40	40	40	40	39	39	39	39	39	39	39	39	38	39	38	38	38
Tue	37	37	36	36	35	34	34	33	32	32	31	31	31	30	31	31	32	33	34	33	33	33	33	33

Day	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23
Wed	37	36	35	34	34	33	32	32	32	32	32	32	32	32	32	33	33	34	34	34	35	35	35	34
Thu	35	35	35	36	36	37	37	37	37	37	37	37	37	37	37	37	38	39	39	39	39	38	38	37
Fri	37	36	36	35	35	35	34	34	34	34	34	34	35	35	35	36	37	37	38	37	37	37	37	37
Sat	37	37	38	38	39	39	39	39	39	40	40	39	39	39	39	40	41	41	41	40	39	39	39	39
Sun	39	39	40	40	40	40	40	40	40	41	41	41	42	42	42	43	44	43	44	44	43	43	42	41
Mon	41	41	40	40	40	40	40	40	40	40	40	39	39	39	39	39	39	39	39	38	39	38	38	38
Tue	37	37	36	36	35	34	34	33	32	32	31	31	31	30	31	31	32	33	34	33	33	33	33	33

Day	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23
Wed	37	36	35	34	34	33	32	32	32	32	32	32	32	32	32	33	33	34	34	34	35	35	35	34
Thu	35	35	35	36	36	37	37	37	37	37	37	37	37	37	37	37	38	39	39	39	39	38	38	37
Fri	37	36	36	35	35	35	34	34	34	34	34	34	35	35	35	36	37	37	38	37	37	37	37	37
Sat	37	37	38	38	39	39	39	39	39	40	40	39	39	39	39	40	41	41	41	40	39	39	39	39
Sun	39	39	40	40	40	40	40	40	40	41	41	41	42	42	42	43	44	43	44	44	43	43	42	41
Mon	41	41	40	40	40	40	40	40	40	40	40	39	39	39	39	39	39	39	39	38	39	38	38	38
Tue	37	37	36	36	35	34	34	33	32	32	31	31	31	30	31	31	32	33	34	33	33	33	33	33