Average annual temperature is 27.0 °C
Absolute maximum temperature: 39.3 °C
Absolute minimum temperature: 17.8 °C
Number of sunny days: 90 days
Number of rainy days: 275 days
Look at detailed online map of Omanthai
* Weather data for Omanthai 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) | 28.6 | 30.6 | 35.0 | 37.2 | 36.6 | 37.5 | 38.8 | 39.3 | 36.4 | 34.6 | 30.9 | 30.8 |
| Average daytime temperature (°C) | 27.6 | 28.9 | 31.8 | 34.3 | 32.9 | 34.6 | 35.4 | 36.8 | 34.1 | 31.9 | 29.2 | 28.4 |
| Average temperature (°C) | 23.6 | 24.3 | 26.5 | 27.8 | 28.0 | 29.4 | 29.5 | 29.5 | 28.3 | 26.3 | 25.1 | 25.1 |
| Average night temperature (°C) | 20.4 | 20.7 | 22.6 | 23.5 | 24.8 | 25.9 | 25.7 | 25.1 | 24.7 | 23.2 | 22.6 | 22.9 |
| Absolute minimum temperature (°C) | 17.8 | 18.6 | 21.5 | 21.9 | 22.9 | 24.8 | 24.8 | 24.1 | 23.9 | 21.8 | 21.9 | 22.5 |
| 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 | 11.8 | 12.1 | 12.3 | 12.5 | 12.6 | 12.6 | 12.4 | 12.2 | 11.9 | 11.7 | 11.6 |
| 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) | 9.1 | 10.2 | 10.9 | 10.5 | 8.9 | 10.5 | 9.8 | 10.7 | 10.0 | 9.1 | 6.9 | 7.5 |
| Precipitation (mm) | 111 | 97 | 57 | 134 | 113 | 28 | 35 | 87 | 76 | 335 | 465 | 264 |
| Sunny days | 16 | 16 | 9 | 9 | 6 | 7 | 10 | 11 | 4 | 1 | 0 | 1 |
| Rainy days | 15 | 12 | 22 | 21 | 25 | 23 | 21 | 20 | 26 | 30 | 30 | 30 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The largest precipitation sum in Omanthai is at