Air quality
Air quality in Colombo today
Updated
Good (US AQI 36) Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. Model estimate for Mon, Oct 26, 7:30 am (02:00 UTC).
Live AQI, PM2.5, PM10 and ozone for Colombo, Western Province, Sri Lanka, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 36 Good
- PM2.5
- 8.9 µg/m³ 0.6× WHO 24-h guideline
- PM10
- 11 µg/m³
- Ozone
- 49 µg/m³
- Dominant pollutant
- PM2.5 sub-index 36
- Best hour today
- 7:30 am AQI 36
- European AQI
- 28
Air quality in Colombo right now
Right now the modelled US Air Quality Index for Colombo, Western Province, Sri Lanka is 36, which falls in the "Good" band (up to 50). Air quality is satisfactory and poses little or no risk; a good time for outdoor activity.
The index is driven mainly by PM2.5, whose own sub-index is 36. Fine and coarse particles come from traffic, heating, industry, dust and smoke; they build up on calm nights and clear when wind or rain arrives.
PM2.5 is 8.9 µg/m³, within the WHO 24-hour guideline of 15 µg/m³; PM10 is 11 µg/m³ against a guideline of 45; ozone is 49 µg/m³ (below the WHO 8-hour level of 100); nitrogen dioxide is 12 µg/m³ (below the 24-hour guideline of 25).
Also this hour: UV index 0.7, carbon monoxide 250 µg/m³.
Colombo AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 36 around Mon 7:30 am to 51 around Tue 7:30 am, from "Good" at best to "Moderate" at worst.
The following day is expected to be worse, averaging about 53 against 45 for the next 24 hours.
| Local time (Asia/Colombo) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Mon 7:30 am | 36 | Good | 8.9 | 11 | 49 |
| Mon 10:30 am | 40 | Good | 11.1 | 14 | 70 |
| Mon 1:30 pm | 43 | Good | 8.4 | 11 | 82 |
| Mon 4:30 pm | 45 | Good | 8.6 | 10 | 65 |
| Mon 7:30 pm | 46 | Good | 9.1 | 10 | 49 |
| Mon 10:30 pm | 46 | Good | 9.7 | 11 | 54 |
| Tue 1:30 am | 47 | Good | 6.5 | 8 | 61 |
| Tue 4:30 am | 49 | Good | 8.8 | 11 | 74 |
| Tue 7:30 am | 51 | Moderate | 15 | 17 | 80 |
| Tue 10:30 am | 52 | Moderate | 14.9 | 17 | 98 |
| Tue 1:30 pm | 53 | Moderate | 10.6 | 12 | 84 |
| Tue 4:30 pm | 54 | Moderate | 9.7 | 10 | 56 |
| Tue 7:30 pm | 54 | Moderate | 11.1 | 12 | 44 |
| Tue 10:30 pm | 54 | Moderate | 8.4 | 10 | 42 |
| Wed 1:30 am | 54 | Moderate | 6.1 | 8 | 53 |
| Wed 4:30 am | 54 | Moderate | 6.2 | 8 | 63 |
| Wed 7:30 am | 53 | Moderate | 8.2 | 10 | 65 |
Every third hour of the CAMS forecast via Open-Meteo. US AQI uses rolling averages (24 h for particles, 8 h for ozone), so it moves more slowly than the hourly concentrations.
Best time to be outside in Colombo today
Between 6 am and 9 pm local time, the cleanest air today is forecast around 7:30 am (AQI 36, Good) and the worst around 6:30 pm (AQI 46). That is a swing of 10 points, so a run or walk around 7:30 am is noticeably better.
Air quality in cities near Colombo
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Thoothukudi | 278 km | 34 | Good | 8 |
| Tirunelveli | 311 km | 30 | Good | 6.6 |
| Thiruvananthapuram | 363 km | 39 | Good | 4.9 |
| Madurai | 382 km | 51 | Moderate | 12 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Colombo, so the numbers on this page are model estimates. Models capture regional pollution well but can miss very local sources such as a busy road or a nearby fire.
Advice for sensitive groups
With the AQI at 36, there is no need for sensitive groups to change plans. People with asthma should still carry their reliever inhaler as usual.
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Values on this page are modelled by CAMS (Copernicus) and served by Open-Meteo; they are estimates for the area around the city centre, not readings from an official monitor.
Nearby cities
More for Colombo
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS).