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Weekly Air Quality in Selected Towns of Sri Lanka (03 – 09 November 2025)
On November 9, 2025, Air Quality across Sri Lanka reached unhealthy levels (AQI above 150). Such levels used to be rare, however, with the AQI in Northern India reaching 400 in New Delhi at present. When the wind circulation transports polluted air from the polluted Northern Indian continent to Sri Lanka. The locations recording the poorest air quality were in Provinces: northwest, western, central, northern and eastern.
From November 8–9, several locations again recorded Unhealthy for Sensitive Groups and Unhealthy daily AQI levels, particularly in Digana (121), Battaramulla (103), and Jaffna (104).
During 3–9 November 2025, air quality across Sri Lanka ranged from Good to Unhealthy levels, with daily AQI values varying between 48 and 159. Compared to the previous week, when Unhealthy conditions were mainly concentrated along the Western coastal belt from Colombo and Battaramulla to Chilaw, this week showed relatively improved conditions across most areas.
Summary for 3 – 9 November 2025:
Weekly Air Quality Index (AQI) levels:
- Moderate (AQI 51–100): Akurana, Kurunegala, Colombo-7, Mirihana,
Battaramulla, Ambalangoda, Ambalantota, Puttalam, Trincomalee, Anuradhapura - Unhealthy for Sensitive Groups (AQI 101–150): Digana, Chilaw, Jaffna
Observed fine particulate measurements by the hour for the last week.
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.
AIR QUALITY BASICS
Air pollution, a widely- talked and argued topic today has been a primary cause of unforeseen climatic changes, many health problems associated with respiratory diseases and ecosystem damage. Vehicular and industrial emissions, dust, burning of fossil fuels, open burning of garbage waste and natural phenomena such as volcanoes, wildfires and pollen contribute to air pollution. Polluted air consists of both particulate matter of fine dimensions and gaseous matter. The presence of these impurities decreases the pureness of the air we breathe.
AQI
United States Environmental Protection Agency (US EPA) has set up a standard to measure the level of air pollution by the following 5 major air pollutants:
- Ground- level ozone (O3)
- Particle pollution (PM2.5 and PM10)
- Carbon monoxide (CO)
- Sulphur dioxide (SO2)
- Nitrogen dioxide (NO2)
Particulate matter of diameter less than 2.5 micrometers (PM2.5) and diameter less than 10 micrometers (PM10) and gases, ozone, carbon monoxide, sulphur dioxide and nitrogen dioxide have been identified as major air pollutants.
The AQI standard for ozone and particle pollution according to US EPA comprises of six categories. Each category is assigned a specific colour and corresponds to a different level of health concern. As the scale grows the air quality turns from good to extremely unhealthy.
Access to real- time air quality data from laser air quality sensoring instruments operated by FECT is available at www.cleanair.lk
