Average annual temperature is 13.9 °C
Absolute maximum temperature: 35.5 °C
Absolute minimum temperature: -14.6 °C
Number of sunny days: 126 days
Number of rainy days: 218 days
Number of snow days: 21 days
Look at detailed online map of Iwamotomachi
* Weather data for Iwamotomachi Japan is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 14.7 | 15.3 | 20.0 | 24.8 | 30.7 | 30.4 | 35.5 | 34.8 | 33.3 | 24.8 | 24.0 | 19.3 |
| Average daytime temperature (°C) | 6.6 | 7.7 | 14.6 | 18.3 | 21.7 | 25.4 | 30.9 | 31.5 | 28.6 | 20.1 | 15.4 | 10.7 |
| Average temperature (°C) | 1.1 | 2.5 | 8.8 | 12.0 | 16.1 | 20.9 | 25.7 | 26.7 | 24.1 | 14.6 | 9.3 | 4.4 |
| Average night temperature (°C) | -2.8 | -1.0 | 3.7 | 6.5 | 10.8 | 17.1 | 21.0 | 22.9 | 20.5 | 10.2 | 4.7 | 0.2 |
| Absolute minimum temperature (°C) | -14.6 | -5.4 | -3.1 | -1.9 | 1.9 | 8.8 | 17.6 | 19.1 | 14.1 | 5.6 | -1.5 | -3.8 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 14.0 | 14.0 | 12.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 10.0 | 10.9 | 12.0 | 13.1 | 14.1 | 14.6 | 14.4 | 13.5 | 12.4 | 11.3 | 10.2 | 9.7 |
| Daylight minimum duration (h) | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 | 9.0 |
| Sunshine mean duration (h) | 7.2 | 7.7 | 8.3 | 9.1 | 8.8 | 7.9 | 10.1 | 10.3 | 8.7 | 8.8 | 7.7 | 7.7 |
| Precipitation (mm) | 32 | 45 | 103 | 77 | 166 | 293 | 164 | 109 | 206 | 87 | 56 | 53 |
| Sunny days | 12 | 12 | 13 | 15 | 14 | 8 | 5 | 4 | 1 | 12 | 13 | 17 |
| Rainy days | 7 | 10 | 18 | 15 | 17 | 22 | 26 | 27 | 29 | 19 | 17 | 11 |
| Snow days | 12 | 6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3 |
The largest precipitation sum in Iwamotomachi is at