Average annual temperature is 15.8 °C
Absolute maximum temperature: 36.8 °C
Absolute minimum temperature: -4.8 °C
Number of sunny days: 113 days
Number of rainy days: 241 days
Number of snow days: 11 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) | 13.9 | 11.5 | 20.2 | 21.9 | 27.6 | 30.6 | 33.1 | 36.8 | 32.9 | 25.3 | 25.0 | 23.5 |
| Average daytime temperature (°C) | 5.7 | 6.0 | 12.7 | 16.1 | 20.2 | 24.8 | 29.6 | 32.8 | 29.0 | 20.4 | 16.0 | 10.5 |
| Average temperature (°C) | 3.4 | 3.6 | 8.9 | 12.9 | 17.2 | 22.1 | 26.9 | 29.6 | 25.9 | 17.2 | 13.0 | 7.6 |
| Average night temperature (°C) | 1.2 | 1.4 | 5.8 | 10.0 | 14.5 | 19.7 | 24.4 | 26.8 | 23.4 | 14.7 | 10.3 | 5.1 |
| Absolute minimum temperature (°C) | -4.8 | -2.5 | 0.2 | 3.8 | 8.6 | 16.7 | 20.9 | 24.7 | 18.3 | 9.2 | 3.5 | -1.1 |
| 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 | 14.7 | 14.4 | 13.5 | 12.4 | 11.2 | 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) | 4.7 | 5.5 | 7.8 | 8.0 | 8.7 | 8.1 | 9.6 | 11.2 | 8.1 | 8.2 | 5.8 | 4.2 |
| Precipitation (mm) | 465 | 260 | 186 | 186 | 251 | 310 | 177 | 100 | 209 | 240 | 397 | 494 |
| Sunny days | 2 | 5 | 16 | 13 | 16 | 8 | 13 | 12 | 5 | 11 | 6 | 6 |
| Rainy days | 24 | 17 | 15 | 17 | 15 | 22 | 18 | 19 | 25 | 20 | 24 | 25 |
| Snow days | 5 | 6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Koshi during the most sunny months:
The largest precipitation sum in Koshi is at