18 – 24 Mar 2026 · Thailand · Wednesday to Tuesday, UTC+7

Thailand weekly air quality

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

83.8Weekly mean modelled AQI · Moderate

Mean PM2.5: 24.4 µg/m³. Both means cover the selected cities hour by hour. They are not a national average or Thailand’s official index.

-1.1 AQI compared with the previous week’s mean of 84.9.

Highest hourly estimate: 179 in Khon Kaen · 18 Mar, 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, 18 Mar	84.6Moderate	50–179	25.4	192 / 192
Thu, 19 Mar	85.1Moderate	52–168	23.7	192 / 192
Fri, 20 Mar	82.3Moderate	53–157	24.2	192 / 192
Sat, 21 Mar	86.9Moderate	52–165	27.7	192 / 192
Sun, 22 Mar	87.2Moderate	51–152	25.8	192 / 192
Mon, 23 Mar	80.5Moderate	51–163	22.1	192 / 192
Tue, 24 Mar	80.3Moderate	52–148	22.3	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	81	81	80	80	80	79	79	79	80	80	80	80	80	81	81	82	93	101	103	100	93	89	85	83
Thu	82	83	82	82	82	82	82	82	81	80	80	80	80	80	80	87	94	101	102	98	93	87	83	79
Fri	79	79	78	78	78	78	78	77	77	78	78	78	78	78	83	88	93	98	98	92	86	84	82	80
Sat	80	80	81	81	82	83	83	84	84	85	85	85	85	85	85	89	95	101	101	97	92	89	86	86
Sun	87	87	87	87	87	87	86	86	86	85	84	84	84	84	84	86	89	94	96	94	91	88	87	86
Mon	84	83	82	82	82	81	81	81	80	79	79	79	78	78	78	77	79	84	86	85	82	80	78	77
Tue	77	76	76	76	76	75	75	76	76	75	75	75	75	75	76	79	89	97	101	98	91	84	80	77

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	117.8Unhealthy for Sensitive Groups	179	38.2	168 / 168
Chiang Rai	117.3Unhealthy for Sensitive Groups	156	41.1	168 / 168
Nakhon Ratchasima	104Unhealthy for Sensitive Groups	149	35.5	168 / 168
Chiang Mai	92.9Moderate	151	27.3	168 / 168
Bangkok	67.6Moderate	88	17.7	168 / 168
Pattaya	58.9Moderate	72	13.4	168 / 168
Phuket	58.6Moderate	88	11.5	168 / 168
Hat Yai	53.6Moderate	58	11	168 / 168

City-hours by category

Good: 7

Moderate: 974

Unhealthy for Sensitive Groups: 325

Unhealthy: 38

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	81	81	80	80	80	79	79	79	80	80	80	80	80	81	81	82	93	101	103	100	93	89	85	83
Thu	82	83	82	82	82	82	82	82	81	80	80	80	80	80	80	87	94	101	102	98	93	87	83	79
Fri	79	79	78	78	78	78	78	77	77	78	78	78	78	78	83	88	93	98	98	92	86	84	82	80
Sat	80	80	81	81	82	83	83	84	84	85	85	85	85	85	85	89	95	101	101	97	92	89	86	86
Sun	87	87	87	87	87	87	86	86	86	85	84	84	84	84	84	86	89	94	96	94	91	88	87	86
Mon	84	83	82	82	82	81	81	81	80	79	79	79	78	78	78	77	79	84	86	85	82	80	78	77
Tue	77	76	76	76	76	75	75	76	76	75	75	75	75	75	76	79	89	97	101	98	91	84	80	77

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	81	81	80	80	80	79	79	79	80	80	80	80	80	81	81	82	93	101	103	100	93	89	85	83
Thu	82	83	82	82	82	82	82	82	81	80	80	80	80	80	80	87	94	101	102	98	93	87	83	79
Fri	79	79	78	78	78	78	78	77	77	78	78	78	78	78	83	88	93	98	98	92	86	84	82	80
Sat	80	80	81	81	82	83	83	84	84	85	85	85	85	85	85	89	95	101	101	97	92	89	86	86
Sun	87	87	87	87	87	87	86	86	86	85	84	84	84	84	84	86	89	94	96	94	91	88	87	86
Mon	84	83	82	82	82	81	81	81	80	79	79	79	78	78	78	77	79	84	86	85	82	80	78	77
Tue	77	76	76	76	76	75	75	76	76	75	75	75	75	75	76	79	89	97	101	98	91	84	80	77

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	81	81	80	80	80	79	79	79	80	80	80	80	80	81	81	82	93	101	103	100	93	89	85	83
Thu	82	83	82	82	82	82	82	82	81	80	80	80	80	80	80	87	94	101	102	98	93	87	83	79
Fri	79	79	78	78	78	78	78	77	77	78	78	78	78	78	83	88	93	98	98	92	86	84	82	80
Sat	80	80	81	81	82	83	83	84	84	85	85	85	85	85	85	89	95	101	101	97	92	89	86	86
Sun	87	87	87	87	87	87	86	86	86	85	84	84	84	84	84	86	89	94	96	94	91	88	87	86
Mon	84	83	82	82	82	81	81	81	80	79	79	79	78	78	78	77	79	84	86	85	82	80	78	77
Tue	77	76	76	76	76	75	75	76	76	75	75	75	75	75	76	79	89	97	101	98	91	84	80	77