Average annual temperature is 21.0 °C
Absolute maximum temperature: 28.5 °C
Absolute minimum temperature: 15.5 °C
Number of sunny days: 5 days
Number of rainy days: 360 days
Look at detailed online map of Siantar
* Weather data for Siantar Indonesia is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 27.5 | 27.4 | 28.4 | 28.2 | 28.5 | 28.4 | 27.1 | 27.0 | 27.3 | 27.3 | 26.6 | 28.3 |
| Average daytime temperature (°C) | 25.1 | 25.4 | 25.6 | 25.4 | 26.0 | 25.8 | 24.9 | 25.1 | 24.8 | 25.0 | 24.9 | 25.1 |
| Average temperature (°C) | 20.5 | 20.8 | 20.9 | 21.0 | 21.8 | 21.6 | 21.2 | 21.0 | 20.9 | 20.7 | 20.9 | 21.1 |
| Average night temperature (°C) | 17.0 | 17.6 | 17.6 | 17.7 | 18.7 | 18.3 | 18.3 | 17.9 | 18.3 | 17.8 | 18.2 | 18.5 |
| Absolute minimum temperature (°C) | 15.5 | 16.4 | 16.2 | 15.6 | 16.7 | 16.1 | 17.4 | 16.8 | 17.2 | 15.9 | 17.1 | 17.4 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 |
| Daylight mean duration (h) | 12.0 | 12.1 | 12.1 | 12.2 | 12.2 | 12.2 | 12.2 | 12.2 | 12.1 | 12.1 | 12.0 | 12.0 |
| Daylight minimum duration (h) | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 |
| Sunshine mean duration (h) | 7.9 | 9.1 | 7.8 | 7.0 | 8.7 | 8.5 | 8.3 | 7.2 | 6.6 | 6.8 | 6.4 | 6.3 |
| Precipitation (mm) | 290 | 236 | 307 | 277 | 253 | 190 | 199 | 297 | 336 | 328 | 332 | 682 |
| Sunny days | 0 | 1 | 0 | 0 | 0 | 2 | 1 | 0 | 0 | 1 | 0 | 0 |
| Rainy days | 31 | 27 | 31 | 30 | 31 | 28 | 30 | 31 | 30 | 30 | 30 | 31 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The largest precipitation sum in Siantar is at