Weekly Air Quality Update for Sri Lanka
27 October – 02 November 2025
Summary
On 31 October and 1 November 2025, the Western Coastal region (Colombo, Battaramulla to Chilaw) recorded Unhealthy daily AQI levels exceeding 150. The AQI was high on 30 November and 2nd November as well as unhealthy for the vulnerable. The regions in the Western hillslopes including Kandy (Digana and Akurana) and the region of aso reached Unhealthy air quality. Other locations experienced moderate air quality with occasional increases in particulate matter concentrations; air quality across Sri Lanka ranged from “Moderate” to “Unhealthy.”
Regional Wind Transport and Cyclonic Storms
During this period, air pollution was extreme in the Northern Indian Indo-Gangetic Plains downstream of the the Himalayas with AQI exceeding 300. This extreme air pollution was transported to Sri Lanka due to the wind circulation modulation due to the storm in the Arabian sea around 28-31 October. There was a complex interaction of the Arabian sea storm and Cyclone Montha in the Bay of Bengal which may eventually help to bring in cleaner air.
Summary for 27 October – 02 November 2025:
Air Quality Index (AQI) levels:
Moderate (AQI 51–100): Kurunegala, Colombo-7, Mirihana, Ambalangoda, Ambalantota, Puttalam, Trincomalee, Jaffna, Anuradhapura
Unhealthy for Sensitive Groups (AQI 101–150): Akurana, Digana, Battaramulla, Chilaw
Unhealthy (AQI>150): Colombo, Chilaw, Battaramulla.
Battaramulla (Pelawatte) recorded the highest AQI of the week, indicating the poorest air quality, whereas Jaffna reported the lowest AQI, reflecting the cleanest air during this period.
Read more about AQ color scale and real-time air quality stations operated by FECT https://fect.lk/air-quality/
Observed fine particulate measurements by the minute for last days
Air Quality impact on human health
Fine particulate matter (PM 2.5) are generally 2.5 microns and smaller in size. Such particles are inhalable and easily lodges inside the lungs reducing capacity. PM2.5 is a concern for people’s health when levels in the air are high. The levels of risk are shown in the dial shown against the US EPA air quality standards. AQ has a scale that run from 0-500, that tells you how clean or polluted your air is. Each level on the scale corresponds to a different level of health concern.