Average annual temperature is 27.0 °C
Absolute maximum temperature: 39.6 °C
Absolute minimum temperature: 19.9 °C
Number of sunny days: 48 days
Number of rainy days: 317 days
Look at detailed online map of Siyambalanduwa
* Weather data for Siyambalanduwa 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) | 29.5 | 30.5 | 33.0 | 35.3 | 35.6 | 37.0 | 39.1 | 39.6 | 35.9 | 32.2 | 31.1 | 30.7 |
| Average daytime temperature (°C) | 28.2 | 28.6 | 30.2 | 32.2 | 32.7 | 35.6 | 35.9 | 37.6 | 33.1 | 30.7 | 29.6 | 28.8 |
| Average temperature (°C) | 24.4 | 24.8 | 25.8 | 27.1 | 27.7 | 29.4 | 29.5 | 30.3 | 27.9 | 25.9 | 25.4 | 25.4 |
| Average night temperature (°C) | 21.6 | 22.1 | 22.6 | 23.5 | 24.2 | 25.3 | 25.1 | 25.4 | 24.8 | 23.2 | 23.0 | 23.2 |
| Absolute minimum temperature (°C) | 19.9 | 20.4 | 21.8 | 21.9 | 22.9 | 24.0 | 23.2 | 24.2 | 23.4 | 22.1 | 22.1 | 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) | 11.8 | 11.9 | 12.1 | 12.3 | 12.4 | 12.5 | 12.5 | 12.3 | 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) | 9.1 | 9.0 | 9.5 | 9.9 | 9.4 | 10.5 | 9.6 | 10.9 | 9.6 | 8.3 | 7.4 | 7.2 |
| Precipitation (mm) | 125 | 179 | 123 | 92 | 179 | 58 | 69 | 38 | 110 | 368 | 530 | 398 |
| Sunny days | 7 | 8 | 3 | 0 | 8 | 4 | 7 | 7 | 3 | 0 | 0 | 1 |
| Rainy days | 24 | 20 | 28 | 30 | 23 | 26 | 24 | 24 | 27 | 31 | 30 | 30 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The largest precipitation sum in Siyambalanduwa is at