PM2.5 exceeds standard in 26 provinces; haze risk to persist in Bangkok region until Feb 3

PM2.5 breaches standard in 26 provinces

The Center for Air Pollution Mitigation (CAPM) at the Pollution Control Department (PCD) reported that PM2.5 levels exceeded the standard in 26 provinces as of 7.00am on 27 January 2026.

The provinces were Pathum Thani, Bangkok, Nonthaburi, Nakhon Pathom, Samut Sakhon, Samut Prakan, Nan, Phitsanulok, Uthai Thani, Chai Nat, Sing Buri, Lopburi, Saraburi, Ang Thong, Suphan Buri, Phra Nakhon Si Ayutthaya, Ratchaburi, Samut Songkhram, Phetchaburi, Prachin Buri, Sa Kaeo, Chachoengsao, Chon Buri, Rayong, Nong Khai and Khon Kaen.

Regional readings

CAPM reported the following PM2.5 readings by region:

• North: Above-standard in three areas, 11.3–47.7 µg/m³
• Northeast: Above-standard in two areas, 11.3–49.3 µg/m³
• Central and West: Above-standard in most areas, 23.1–75.8 µg/m³
• East: Above-standard in most areas, 23.6–53.5 µg/m³
• South: Overall very good, 10.4–22.5 µg/m³
• Bangkok and vicinity: PCD and Bangkok Metropolitan Administration (BMA) stations showed above-standard levels in most areas, 41.9–91.8 µg/m³

Warning: elevated PM2.5 likely to persist until Feb 3

CAPM warned that Bangkok and surrounding provinces, as well as the Central and Western regions, could see PM2.5 remain persistently above the standard from 27 January to 3 February 2026, mostly at the orange level—meaning it is beginning to affect health.

The agency attributed the outlook to reduced ventilation and a “lid-like” atmospheric condition that traps pollutants and prevents them from dispersing, worsening the situation.

It added that on 29–30 January, winds may shift to southerly winds, bringing moisture from the Gulf of Thailand. Combined with suspended particulates, this could lead to hazy skies and poorer visibility.

Health advice and public cooperation

CAPM urged people to take care of their health and avoid outdoor activities. Those who must go outside were advised to wear a face mask and protective gear, and to follow Ministry of Public Health guidance strictly.

To help reduce dust, CAPM called for cooperation to avoid all forms of open burning, reduce vehicle use, and ensure strict controls at factories and construction sites, including suspending dust-generating activities.

Where to check air quality

The public can track updates via the Air4Thai website (Air4Thai.pcd.go.th) or the Air4Thai mobile application.