Average annual temperature is 16.6 °C
Absolute maximum temperature: 35.8 °C
Absolute minimum temperature: -3.2 °C
Number of sunny days: 104 days
Number of rainy days: 255 days
Number of snow days: 6 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) | 15.8 | 14.4 | 22.0 | 22.6 | 25.6 | 29.6 | 33.1 | 35.8 | 31.3 | 24.3 | 26.2 | 21.5 |
| Average daytime temperature (°C) | 8.3 | 9.3 | 15.1 | 17.2 | 21.5 | 25.4 | 29.8 | 32.1 | 27.9 | 21.1 | 16.7 | 11.6 |
| Average temperature (°C) | 6.1 | 6.5 | 11.0 | 14.0 | 18.1 | 22.4 | 26.9 | 28.5 | 25.0 | 17.9 | 13.6 | 8.9 |
| Average night temperature (°C) | 4.0 | 3.7 | 7.2 | 11.0 | 15.0 | 19.7 | 24.2 | 25.7 | 22.8 | 14.7 | 10.6 | 6.4 |
| Absolute minimum temperature (°C) | -3.2 | 0.6 | -0.4 | 4.6 | 8.2 | 15.3 | 20.0 | 23.4 | 18.9 | 9.7 | 3.4 | 0.3 |
| 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 | 13.0 | 12.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 10.1 | 10.9 | 12.0 | 13.1 | 14.0 | 14.5 | 14.3 | 13.5 | 12.4 | 11.3 | 10.3 | 9.8 |
| Daylight minimum duration (h) | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 13.0 | 12.0 | 11.0 | 10.0 | 9.0 | 9.0 |
| Sunshine mean duration (h) | 5.8 | 5.9 | 8.3 | 7.9 | 8.8 | 8.1 | 9.5 | 10.0 | 8.0 | 8.6 | 6.6 | 5.6 |
| Precipitation (mm) | 124 | 110 | 91 | 191 | 255 | 149 | 218 | 215 | 199 | 44 | 117 | 152 |
| Sunny days | 6 | 6 | 16 | 15 | 13 | 9 | 6 | 2 | 2 | 12 | 11 | 6 |
| Rainy days | 23 | 20 | 15 | 15 | 18 | 21 | 25 | 29 | 28 | 19 | 19 | 23 |
| Snow days | 2 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 |
The best time to visit Koshi during the most sunny months:
The largest precipitation sum in Koshi is at