Weekly Air Quality Update for Sri Lanka

Weekly Air Quality Update for Sri Lanka

17 – 23 November 2025

Summary

After a week of poor Air quality the previous week (9-16 Nov), AQ has improved this week (17-23 November, 2025). Last week polluted air was transported from the northern parts of the Indian peninsula and travelled across the Arabian Sea and the Bay of Bengal to Sri Lanka at times. 

In contrast, from 17-23 November, winds coming from the northeast helped clear polluted air by the beginning of the week. Although some polluted air entered Sri Lanka again in the middle of the last week, AQI levels remained improved compared to the previous week across the country.

During the week, overall air quality across Sri Lanka ranged from “Good” to “Unhealthy for Sensitive Groups”. On 20 November, the AQI in Chilaw rose to 106, placing it in the Unhealthy for Sensitive Groups category. Mirihana (Cleanco) reported the highest AQI of the week at 67, while Ambalantota recorded the lowest value at 30, indicating the cleanest air during this period. Most locations recorded Good to Moderate conditions, indicating generally favourable air quality.  

Weekly Air Quality Index (AQI) Levels:

  •    Good (AQI 0-50): Kurunegala, Ambalantota, Puttalam, Trincomalee, Jaffna, Anuradhapura
  •      Moderate (AQI 51-100): Akurana-AV-Outdoor, Digana, Colombo(Gregory’s Road), Mirihana(Cleanco), Battaramulla(CEA), Chilaw(CEA), Ambalangoda
AQDATA_MonitoringV1

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.