Average annual temperature is 12.5 °C
Absolute maximum temperature: 35.3 °C
Absolute minimum temperature: -10.8 °C
Number of sunny days: 103 days
Number of rainy days: 235 days
Number of snow days: 27 days
Look at detailed online map of Koshi
* Weather data for Koshi 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) | 12.5 | 13.9 | 20.8 | 24.3 | 30.9 | 27.8 | 31.4 | 35.3 | 35.1 | 23.3 | 23.4 | 16.4 |
| Average daytime temperature (°C) | 3.5 | 4.2 | 12.5 | 16.8 | 20.5 | 23.9 | 28.2 | 32.5 | 28.2 | 18.3 | 14.0 | 7.9 |
| Average temperature (°C) | -0.5 | 0.4 | 6.4 | 10.6 | 14.7 | 19.4 | 23.8 | 26.7 | 22.8 | 13.0 | 8.5 | 3.1 |
| Average night temperature (°C) | -3.8 | -2.6 | 1.6 | 5.9 | 10.2 | 15.6 | 19.8 | 22.0 | 19.2 | 9.1 | 4.8 | -1.0 |
| Absolute minimum temperature (°C) | -10.8 | -6.8 | -7.8 | 0.4 | 1.9 | 9.5 | 16.2 | 18.8 | 12.1 | 5.5 | -0.6 | -8.6 |
| 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 | 10.8 | 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) | 6.0 | 6.1 | 8.6 | 8.7 | 9.2 | 8.1 | 9.8 | 11.5 | 8.9 | 8.9 | 7.1 | 7.0 |
| Precipitation (mm) | 209 | 145 | 107 | 150 | 207 | 235 | 261 | 27 | 192 | 152 | 180 | 256 |
| Sunny days | 7 | 9 | 15 | 11 | 12 | 3 | 6 | 11 | 6 | 8 | 9 | 6 |
| Rainy days | 12 | 11 | 15 | 19 | 19 | 27 | 25 | 20 | 24 | 23 | 21 | 19 |
| Snow days | 12 | 8 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 6 |
The best time to visit Koshi during the most sunny months:
The largest precipitation sum in Koshi is at