23 – 29 Sep 2026 · Thailand · Wednesday to Tuesday, UTC+7

Thailand weekly air quality

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

40.3Weekly mean modelled AQI · Good

Mean PM2.5: 7.5 µg/m³. Both means cover the selected cities hour by hour. They are not a national average or Thailand’s official index.

-2.1 AQI compared with the previous week’s mean of 42.4.

Highest hourly estimate: 186 in Bangkok · 23 Sept, 19:00 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, 23 Sep	56.9Moderate	28–186	10	192 / 192
Thu, 24 Sep	44.9Good	21–98	9.7	192 / 192
Fri, 25 Sep	43.7Good	19–103	7.1	192 / 192
Sat, 26 Sep	35.4Good	18–64	5	192 / 192
Sun, 27 Sep	29.9Good	14–67	5	192 / 192
Mon, 28 Sep	30.6Good	16–59	5.6	192 / 192
Tue, 29 Sep	40.6Good	18–77	10.2	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	50	51	51	51	51	51	51	51	51	50	49	49	48	48	48	54	67	76	80	78	74	69	62	55
Thu	48	45	45	45	44	44	44	43	43	43	44	44	44	44	45	45	46	49	50	48	45	44	44	43
Fri	43	43	43	43	43	43	42	42	42	42	42	42	43	43	44	45	48	51	50	48	44	43	41	40
Sat	38	38	37	37	36	36	35	35	34	34	34	34	34	35	36	36	37	37	37	36	36	35	34	32
Sun	31	30	30	29	29	29	29	29	29	29	29	29	29	30	30	30	31	31	32	31	31	31	31	30
Mon	30	30	30	30	29	29	29	28	28	27	27	28	28	29	30	32	34	35	36	35	34	33	33	33
Tue	33	34	35	35	36	37	37	37	37	37	38	39	40	41	42	43	44	46	48	48	47	47	48	49

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	57.4Moderate	108	12.9	168 / 168
Bangkok	48.9Good	186	9.5	168 / 168
Phuket	43.9Good	77	8.2	168 / 168
Pattaya	41.4Good	144	7	168 / 168
Hat Yai	39.1Good	65	8.2	168 / 168
Chiang Rai	34.5Good	52	5.7	168 / 168
Khon Kaen	31.2Good	59	5.1	168 / 168
Nakhon Ratchasima	26Good	53	3.4	168 / 168

City-hours by category

Good: 959

Moderate: 367

Unhealthy for Sensitive Groups: 13

Unhealthy: 5

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	50	51	51	51	51	51	51	51	51	50	49	49	48	48	48	54	67	76	80	78	74	69	62	55
Thu	48	45	45	45	44	44	44	43	43	43	44	44	44	44	45	45	46	49	50	48	45	44	44	43
Fri	43	43	43	43	43	43	42	42	42	42	42	42	43	43	44	45	48	51	50	48	44	43	41	40
Sat	38	38	37	37	36	36	35	35	34	34	34	34	34	35	36	36	37	37	37	36	36	35	34	32
Sun	31	30	30	29	29	29	29	29	29	29	29	29	29	30	30	30	31	31	32	31	31	31	31	30
Mon	30	30	30	30	29	29	29	28	28	27	27	28	28	29	30	32	34	35	36	35	34	33	33	33
Tue	33	34	35	35	36	37	37	37	37	37	38	39	40	41	42	43	44	46	48	48	47	47	48	49

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	50	51	51	51	51	51	51	51	51	50	49	49	48	48	48	54	67	76	80	78	74	69	62	55
Thu	48	45	45	45	44	44	44	43	43	43	44	44	44	44	45	45	46	49	50	48	45	44	44	43
Fri	43	43	43	43	43	43	42	42	42	42	42	42	43	43	44	45	48	51	50	48	44	43	41	40
Sat	38	38	37	37	36	36	35	35	34	34	34	34	34	35	36	36	37	37	37	36	36	35	34	32
Sun	31	30	30	29	29	29	29	29	29	29	29	29	29	30	30	30	31	31	32	31	31	31	31	30
Mon	30	30	30	30	29	29	29	28	28	27	27	28	28	29	30	32	34	35	36	35	34	33	33	33
Tue	33	34	35	35	36	37	37	37	37	37	38	39	40	41	42	43	44	46	48	48	47	47	48	49

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	50	51	51	51	51	51	51	51	51	50	49	49	48	48	48	54	67	76	80	78	74	69	62	55
Thu	48	45	45	45	44	44	44	43	43	43	44	44	44	44	45	45	46	49	50	48	45	44	44	43
Fri	43	43	43	43	43	43	42	42	42	42	42	42	43	43	44	45	48	51	50	48	44	43	41	40
Sat	38	38	37	37	36	36	35	35	34	34	34	34	34	35	36	36	37	37	37	36	36	35	34	32
Sun	31	30	30	29	29	29	29	29	29	29	29	29	29	30	30	30	31	31	32	31	31	31	31	30
Mon	30	30	30	30	29	29	29	28	28	27	27	28	28	29	30	32	34	35	36	35	34	33	33	33
Tue	33	34	35	35	36	37	37	37	37	37	38	39	40	41	42	43	44	46	48	48	47	47	48	49