CAPM warns PM2.5 risk from Feb 3–9, with hotspots in Bangkok and Central region

The Center for Air Pollution Mitigation (CAPM) issued a PM2.5 warning for 3–9 February 2026, saying pollution levels are likely to fluctuate by region, with periods of increased accumulation expected in Bangkok and the metropolitan area, the Central and western regions, and parts of the North later in the week.

As of 5.00pm on 2 February, CAPM said PM2.5 had already exceeded the standard in multiple areas, particularly in Bangkok and the metropolitan area, the North and the Central region.

Provinces exceeding the standard on Feb 2

CAPM said above-standard readings were recorded in Nonthaburi, Bangkok, Samut Sakhon, Samut Prakan, Chiang Rai, Nan, Uttaradit, Phitsanulok, Ratchaburi, Samut Songkhram, Phetchaburi and Trat.

Regional snapshot on Feb 2 (5.00pm)

• Northern region: Above the standard in 4 areas; 12.7–49.0 µg/m³
• Northeastern region: Overall good; 12.2–29.5 µg/m³
• Central and western regions: Above the standard in 3 areas; 19.7–55.5 µg/m³
• Eastern region: Above the standard in 1 area; 12.6–39.5 µg/m³
• Southern region: Overall very good; 13.0–30.3 µg/m³
• Bangkok and metropolitan area: Above the standard in 4 areas; 20.2–44.0 µg/m³

PM2.5 warning for Feb 3–9

Based on weather models and wind patterns, CAPM said the next seven days could bring worsening air quality in several regions, with key risk windows as follows:

Bangkok and metropolitan area: higher risk early week (Feb 3–5)

CAPM warned of increased accumulation from 3–5 February due to still conditions and light morning winds, which may reduce dispersion of pollution from traffic and construction. Residents and commuters were advised to keep masks ready.

Central and western regions: prolonged elevated levels (Feb 3–8)

CAPM described the Central-Western belt as the most concerning area, with elevated PM2.5 likely to persist from 3–8 February, due to wind flows that can trap pollution in basin-like terrain and outdoor activities in some provinces.

North and North-east: late-week uptick (Feb 6–8)

CAPM said conditions could become more severe from 6–8 February. It urged extra caution in the North, especially along border-adjacent areas and valleys. In the North-east, CAPM said PM2.5 is expected to begin accumulating again from 6 February as winds change direction.

Eastern region: improvement expected (Feb 8–9)

While some areas may exceed the standard early in the week, CAPM said PM2.5 levels are expected to fall noticeably on 8–9 February as winds improve ventilation.

Southern region: “good to very good” continues

CAPM said the South is expected to retain the best air quality nationwide, with conditions forecast to remain good to very good throughout 3–9 February, supporting outdoor activities and travel.

Health advice

CAPM urged people in affected areas to take precautions:

• General public: Monitor your health; reduce time outdoors if needed, or wear an N95 mask.
• Vulnerable groups (children, the elderly, pregnant women): Limit outdoor activity. Seek medical advice if symptoms occur, including coughing, breathing difficulty or eye irritation.