25 – 31 Mar 2026 · Thailand · Wednesday to Tuesday, UTC+7

Thailand weekly air quality

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

89.3Weekly mean modelled AQI · Moderate

Mean PM2.5: 28.6 µg/m³. Both means cover the selected cities hour by hour. They are not a national average or Thailand’s official index.

+5.5 AQI compared with the previous week’s mean of 83.8.

Highest hourly estimate: 174 in Chiang Rai · 27 Mar, 12:00 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, 25 Mar	82.9Moderate	52–160	26	192 / 192
Thu, 26 Mar	91.8Moderate	52–173	32.5	192 / 192
Fri, 27 Mar	100.5Unhealthy for Sensitive Groups	53–174	32.5	192 / 192
Sat, 28 Mar	91.7Moderate	57–167	27.5	192 / 192
Sun, 29 Mar	83.9Moderate	51–142	25.5	192 / 192
Mon, 30 Mar	87.3Moderate	46–162	27.1	192 / 192
Tue, 31 Mar	86.7Moderate	40–160	29	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	76	76	76	76	77	77	77	78	78	79	79	80	80	80	80	83	92	98	100	95	91	89	87	86
Thu	86	85	84	84	84	84	84	84	85	86	87	88	89	89	90	93	100	109	112	107	101	98	97	97
Fri	97	97	97	97	97	98	98	98	98	98	98	98	98	98	98	100	109	114	114	110	106	101	98	96
Sat	94	93	92	92	91	91	90	90	90	90	90	90	90	89	89	90	95	101	102	96	92	89	88	87
Sun	86	86	85	85	85	84	84	83	83	82	82	82	82	82	82	82	85	90	90	86	83	82	82	83
Mon	83	83	83	84	84	84	85	85	85	86	85	86	86	86	87	90	94	98	99	94	91	88	86	86
Tue	85	85	85	85	85	84	84	84	84	84	83	83	83	83	85	87	90	94	96	95	92	89	87	87

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 Rai	141Unhealthy for Sensitive Groups	174	59.6	168 / 168
Chiang Mai	113.9Unhealthy for Sensitive Groups	162	42.9	168 / 168
Khon Kaen	110.5Unhealthy for Sensitive Groups	173	35.7	168 / 168
Nakhon Ratchasima	99Moderate	128	32.9	168 / 168
Bangkok	69.8Moderate	105	17.9	168 / 168
Pattaya	61.4Moderate	72	14.9	168 / 168
Hat Yai	59.3Moderate	67	13.8	168 / 168
Phuket	59.2Moderate	100	11	168 / 168

City-hours by category

Good: 30

Moderate: 851

Unhealthy for Sensitive Groups: 354

Unhealthy: 109

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	76	76	76	76	77	77	77	78	78	79	79	80	80	80	80	83	92	98	100	95	91	89	87	86
Thu	86	85	84	84	84	84	84	84	85	86	87	88	89	89	90	93	100	109	112	107	101	98	97	97
Fri	97	97	97	97	97	98	98	98	98	98	98	98	98	98	98	100	109	114	114	110	106	101	98	96
Sat	94	93	92	92	91	91	90	90	90	90	90	90	90	89	89	90	95	101	102	96	92	89	88	87
Sun	86	86	85	85	85	84	84	83	83	82	82	82	82	82	82	82	85	90	90	86	83	82	82	83
Mon	83	83	83	84	84	84	85	85	85	86	85	86	86	86	87	90	94	98	99	94	91	88	86	86
Tue	85	85	85	85	85	84	84	84	84	84	83	83	83	83	85	87	90	94	96	95	92	89	87	87

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	76	76	76	76	77	77	77	78	78	79	79	80	80	80	80	83	92	98	100	95	91	89	87	86
Thu	86	85	84	84	84	84	84	84	85	86	87	88	89	89	90	93	100	109	112	107	101	98	97	97
Fri	97	97	97	97	97	98	98	98	98	98	98	98	98	98	98	100	109	114	114	110	106	101	98	96
Sat	94	93	92	92	91	91	90	90	90	90	90	90	90	89	89	90	95	101	102	96	92	89	88	87
Sun	86	86	85	85	85	84	84	83	83	82	82	82	82	82	82	82	85	90	90	86	83	82	82	83
Mon	83	83	83	84	84	84	85	85	85	86	85	86	86	86	87	90	94	98	99	94	91	88	86	86
Tue	85	85	85	85	85	84	84	84	84	84	83	83	83	83	85	87	90	94	96	95	92	89	87	87

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	76	76	76	76	77	77	77	78	78	79	79	80	80	80	80	83	92	98	100	95	91	89	87	86
Thu	86	85	84	84	84	84	84	84	85	86	87	88	89	89	90	93	100	109	112	107	101	98	97	97
Fri	97	97	97	97	97	98	98	98	98	98	98	98	98	98	98	100	109	114	114	110	106	101	98	96
Sat	94	93	92	92	91	91	90	90	90	90	90	90	90	89	89	90	95	101	102	96	92	89	88	87
Sun	86	86	85	85	85	84	84	83	83	82	82	82	82	82	82	82	85	90	90	86	83	82	82	83
Mon	83	83	83	84	84	84	85	85	85	86	85	86	86	86	87	90	94	98	99	94	91	88	86	86
Tue	85	85	85	85	85	84	84	84	84	84	83	83	83	83	85	87	90	94	96	95	92	89	87	87