16 – 22 Sep 2026 · Thailand · Wednesday to Tuesday, UTC+7

Thailand weekly air quality

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

42.4Weekly mean modelled AQI · Good

Mean PM2.5: 8.2 µg/m³. Both means cover the selected cities hour by hour. They are not a national average or Thailand’s official index.

-7.7 AQI compared with the previous week’s mean of 50.1.

Highest hourly estimate: 109 in Hat Yai · 16 Sept, 08:00 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, 16 Sep	56.4Moderate	23–109	10.6	192 / 192
Thu, 17 Sep	45.3Good	19–85	8.3	192 / 192
Fri, 18 Sep	37.6Good	17–62	5.8	192 / 192
Sat, 19 Sep	36.5Good	18–58	7	192 / 192
Sun, 20 Sep	36.9Good	20–62	6.4	192 / 192
Mon, 21 Sep	37.9Good	23–66	7.7	192 / 192
Tue, 22 Sep	46.1Good	20–96	11.3	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	58	58	58	58	59	59	59	59	59	58	58	57	57	56	56	55	57	58	58	56	53	51	50	49
Thu	49	48	47	47	46	46	45	45	45	45	44	44	44	44	44	44	44	48	49	46	44	43	43	43
Fri	43	43	43	42	41	40	39	39	38	37	36	36	36	36	36	35	36	37	38	37	36	35	34	33
Sat	32	32	32	32	32	32	33	33	33	34	35	35	36	37	38	40	41	42	42	42	42	41	40	39
Sun	38	38	37	37	36	36	36	36	36	35	35	35	35	35	36	37	38	40	41	41	40	38	37	35
Mon	35	35	35	36	36	36	36	37	36	36	36	36	36	36	37	39	41	43	44	43	42	41	40	39
Tue	39	39	39	39	40	40	41	41	43	44	46	47	47	48	49	50	52	55	55	53	51	51	51	50

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	58.4Moderate	96	13.5	168 / 168
Bangkok	51.5Moderate	91	11.2	168 / 168
Hat Yai	43.7Good	109	8.1	168 / 168
Khon Kaen	43.5Good	70	8.5	168 / 168
Nakhon Ratchasima	41.9Good	57	7.9	168 / 168
Phuket	34.8Good	46	6.4	168 / 168
Pattaya	33Good	57	5	168 / 168
Chiang Rai	32.3Good	53	4.7	168 / 168

City-hours by category

Good: 908

Moderate: 425

Unhealthy for Sensitive Groups: 11

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	58	58	58	58	59	59	59	59	59	58	58	57	57	56	56	55	57	58	58	56	53	51	50	49
Thu	49	48	47	47	46	46	45	45	45	45	44	44	44	44	44	44	44	48	49	46	44	43	43	43
Fri	43	43	43	42	41	40	39	39	38	37	36	36	36	36	36	35	36	37	38	37	36	35	34	33
Sat	32	32	32	32	32	32	33	33	33	34	35	35	36	37	38	40	41	42	42	42	42	41	40	39
Sun	38	38	37	37	36	36	36	36	36	35	35	35	35	35	36	37	38	40	41	41	40	38	37	35
Mon	35	35	35	36	36	36	36	37	36	36	36	36	36	36	37	39	41	43	44	43	42	41	40	39
Tue	39	39	39	39	40	40	41	41	43	44	46	47	47	48	49	50	52	55	55	53	51	51	51	50

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	58	58	58	58	59	59	59	59	59	58	58	57	57	56	56	55	57	58	58	56	53	51	50	49
Thu	49	48	47	47	46	46	45	45	45	45	44	44	44	44	44	44	44	48	49	46	44	43	43	43
Fri	43	43	43	42	41	40	39	39	38	37	36	36	36	36	36	35	36	37	38	37	36	35	34	33
Sat	32	32	32	32	32	32	33	33	33	34	35	35	36	37	38	40	41	42	42	42	42	41	40	39
Sun	38	38	37	37	36	36	36	36	36	35	35	35	35	35	36	37	38	40	41	41	40	38	37	35
Mon	35	35	35	36	36	36	36	37	36	36	36	36	36	36	37	39	41	43	44	43	42	41	40	39
Tue	39	39	39	39	40	40	41	41	43	44	46	47	47	48	49	50	52	55	55	53	51	51	51	50

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	58	58	58	58	59	59	59	59	59	58	58	57	57	56	56	55	57	58	58	56	53	51	50	49
Thu	49	48	47	47	46	46	45	45	45	45	44	44	44	44	44	44	44	48	49	46	44	43	43	43
Fri	43	43	43	42	41	40	39	39	38	37	36	36	36	36	36	35	36	37	38	37	36	35	34	33
Sat	32	32	32	32	32	32	33	33	33	34	35	35	36	37	38	40	41	42	42	42	42	41	40	39
Sun	38	38	37	37	36	36	36	36	36	35	35	35	35	35	36	37	38	40	41	41	40	38	37	35
Mon	35	35	35	36	36	36	36	37	36	36	36	36	36	36	37	39	41	43	44	43	42	41	40	39
Tue	39	39	39	39	40	40	41	41	43	44	46	47	47	48	49	50	52	55	55	53	51	51	51	50