20 – 26 May 2026 · Thailand · Wednesday to Tuesday, UTC+7

Thailand weekly air quality

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

53.8Weekly mean modelled AQI · Moderate

Mean PM2.5: 12.3 µg/m³. Both means cover the selected cities hour by hour. They are not a national average or Thailand’s official index.

+0.4 AQI compared with the previous week’s mean of 53.4.

Highest hourly estimate: 91 in Khon Kaen · 21 May, 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, 20 May	50.4Moderate	20–86	12.4	192 / 192
Thu, 21 May	55.1Moderate	22–91	14.1	192 / 192
Fri, 22 May	58.4Moderate	31–88	14.5	192 / 192
Sat, 23 May	54.5Moderate	28–79	10.9	192 / 192
Sun, 24 May	53.1Moderate	31–71	11.8	192 / 192
Mon, 25 May	54.1Moderate	32–71	11.6	192 / 192
Tue, 26 May	51.2Moderate	25–69	10.7	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	52	52	52	51	51	50	49	49	48	48	48	48	48	48	49	49	50	53	54	54	53	52	52	51
Thu	52	52	52	52	53	53	53	54	54	55	55	55	55	56	56	56	57	60	60	58	56	56	56	56
Fri	56	56	56	56	56	57	57	57	58	58	59	59	60	60	60	60	60	60	60	60	60	59	60	59
Sat	59	59	59	59	58	58	58	57	56	55	55	54	53	53	52	52	51	52	52	51	51	51	51	52
Sun	52	52	52	52	52	52	53	53	53	53	53	53	53	53	53	54	54	54	54	54	54	54	54	54
Mon	54	54	54	54	54	55	54	54	54	54	54	54	54	54	55	54	54	54	54	54	54	54	53	53
Tue	53	53	52	52	52	52	52	52	52	52	51	51	50	50	50	50	50	50	50	51	51	52	52	52

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
Khon Kaen	69.1Moderate	91	18.5	168 / 168
Nakhon Ratchasima	65.7Moderate	78	16.9	168 / 168
Chiang Rai	63.3Moderate	74	15.4	168 / 168
Chiang Mai	57.9Moderate	86	12.8	168 / 168
Bangkok	53.4Moderate	65	11.4	168 / 168
Hat Yai	45.7Good	68	9.5	168 / 168
Phuket	40.9Good	58	8	168 / 168
Pattaya	34.4Good	46	5.8	168 / 168

City-hours by category

Good: 419

Moderate: 925

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	52	52	52	51	51	50	49	49	48	48	48	48	48	48	49	49	50	53	54	54	53	52	52	51
Thu	52	52	52	52	53	53	53	54	54	55	55	55	55	56	56	56	57	60	60	58	56	56	56	56
Fri	56	56	56	56	56	57	57	57	58	58	59	59	60	60	60	60	60	60	60	60	60	59	60	59
Sat	59	59	59	59	58	58	58	57	56	55	55	54	53	53	52	52	51	52	52	51	51	51	51	52
Sun	52	52	52	52	52	52	53	53	53	53	53	53	53	53	53	54	54	54	54	54	54	54	54	54
Mon	54	54	54	54	54	55	54	54	54	54	54	54	54	54	55	54	54	54	54	54	54	54	53	53
Tue	53	53	52	52	52	52	52	52	52	52	51	51	50	50	50	50	50	50	50	51	51	52	52	52

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	52	52	52	51	51	50	49	49	48	48	48	48	48	48	49	49	50	53	54	54	53	52	52	51
Thu	52	52	52	52	53	53	53	54	54	55	55	55	55	56	56	56	57	60	60	58	56	56	56	56
Fri	56	56	56	56	56	57	57	57	58	58	59	59	60	60	60	60	60	60	60	60	60	59	60	59
Sat	59	59	59	59	58	58	58	57	56	55	55	54	53	53	52	52	51	52	52	51	51	51	51	52
Sun	52	52	52	52	52	52	53	53	53	53	53	53	53	53	53	54	54	54	54	54	54	54	54	54
Mon	54	54	54	54	54	55	54	54	54	54	54	54	54	54	55	54	54	54	54	54	54	54	53	53
Tue	53	53	52	52	52	52	52	52	52	52	51	51	50	50	50	50	50	50	50	51	51	52	52	52

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	52	52	52	51	51	50	49	49	48	48	48	48	48	48	49	49	50	53	54	54	53	52	52	51
Thu	52	52	52	52	53	53	53	54	54	55	55	55	55	56	56	56	57	60	60	58	56	56	56	56
Fri	56	56	56	56	56	57	57	57	58	58	59	59	60	60	60	60	60	60	60	60	60	59	60	59
Sat	59	59	59	59	58	58	58	57	56	55	55	54	53	53	52	52	51	52	52	51	51	51	51	52
Sun	52	52	52	52	52	52	53	53	53	53	53	53	53	53	53	54	54	54	54	54	54	54	54	54
Mon	54	54	54	54	54	55	54	54	54	54	54	54	54	54	55	54	54	54	54	54	54	54	53	53
Tue	53	53	52	52	52	52	52	52	52	52	51	51	50	50	50	50	50	50	50	51	51	52	52	52