Weekly Air Quality Update for Sri Lanka

01 - 07 December 2025

Summary

After Cyclone Ditwah moved away from the country, polluted air began entering Sri Lanka from the Arabian Sea. From 01 to 03 December, many areas recorded “Unhealthy” AQI values. On 02 December, Chilaw reported a daily AQI of 200, which falls under the “Very Unhealthy” category.

After 03 December, some of the polluted air was cleared by cleaner air arriving from the direction of the Bay of Bengal. Following this, most areas recorded Moderate AQI values, while some locations even recorded Good daily AQI levels.

During the week, overall air quality across Sri Lanka ranged from “Good” to “Very Unhealthy.”

For the week as a whole, AQI values ranged from Moderate to Unhealthy for Sensitive Groups. Digana recorded the highest weekly AQI at 139, while Ambalanthota reported the lowest at 75.

Weekly Air Quality Index (AQI) Levels:

Moderate (AQI 51-100 ): Kurunegala, Ambalanthota, Puttalam, Trincomalee, Jaffna, Anuradhapura
Unhealthy for Sensitive Groups (AQI 101-150): Akurana-AV-Outdoor, Digana, Colombo(Gregory Road), Mirihana, Battaramulla(CEA), Chilaw(CEA), Ambalangoda

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

The AQ variation at a fine temporal scale is shown in Colombo and Pelawatte for the last three days. The peak value in Colombo was about 90, and in Pelawatte was about 150.

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.