Average annual temperature is 22.7 °C
Absolute maximum temperature: 30.3 °C
Absolute minimum temperature: 16.1 °C
Number of sunny days: 29 days
Number of rainy days: 336 days
Look at detailed online map of Koswana
* Weather data for Koswana Sri Lanka is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 25.1 | 26.3 | 29.4 | 30.3 | 29.5 | 28.0 | 27.5 | 30.3 | 27.2 | 27.6 | 27.4 | 27.3 |
| Average daytime temperature (°C) | 23.9 | 25.1 | 27.0 | 28.4 | 27.0 | 26.4 | 25.5 | 28.0 | 25.5 | 26.0 | 26.2 | 25.4 |
| Average temperature (°C) | 20.7 | 21.5 | 22.8 | 23.7 | 23.6 | 23.3 | 22.8 | 23.7 | 22.6 | 22.6 | 22.6 | 22.4 |
| Average night temperature (°C) | 18.0 | 18.3 | 19.5 | 20.1 | 21.4 | 21.4 | 21.0 | 21.1 | 20.9 | 20.4 | 20.3 | 20.5 |
| Absolute minimum temperature (°C) | 16.1 | 16.1 | 18.6 | 18.5 | 20.8 | 20.7 | 20.1 | 20.3 | 20.1 | 19.1 | 18.7 | 18.8 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 11.0 | 11.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 11.0 | 11.0 |
| Daylight mean duration (h) | 11.7 | 11.9 | 12.1 | 12.3 | 12.5 | 12.5 | 12.5 | 12.4 | 12.2 | 12.0 | 11.8 | 11.7 |
| Daylight minimum duration (h) | 11.0 | 11.0 | 11.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 11.0 | 11.0 | 11.0 |
| Sunshine mean duration (h) | 9.2 | 9.6 | 10.1 | 10.1 | 9.3 | 10.3 | 9.2 | 10.8 | 8.5 | 7.9 | 7.7 | 7.4 |
| Precipitation (mm) | 84 | 70 | 99 | 167 | 146 | 107 | 143 | 53 | 192 | 462 | 669 | 303 |
| Sunny days | 10 | 8 | 3 | 4 | 1 | 0 | 1 | 0 | 0 | 1 | 0 | 1 |
| Rainy days | 21 | 20 | 28 | 26 | 30 | 30 | 30 | 31 | 30 | 30 | 30 | 30 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The largest precipitation sum in Koswana is at