Average annual temperature is 13.2 °C
Absolute maximum temperature: 35.2 °C
Absolute minimum temperature: -12.1 °C
Number of sunny days: 104 days
Number of rainy days: 239 days
Number of snow days: 22 days
Look at detailed online map of Koizumi
* Weather data for Koizumi 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) | 14.0 | 13.8 | 19.8 | 22.2 | 31.4 | 29.7 | 35.2 | 34.5 | 31.4 | 25.2 | 23.0 | 16.1 |
| Average daytime temperature (°C) | 4.0 | 5.1 | 13.1 | 16.9 | 20.4 | 24.3 | 29.1 | 31.5 | 27.5 | 19.6 | 13.6 | 7.8 |
| Average temperature (°C) | 0.4 | 1.1 | 7.1 | 11.1 | 15.3 | 20.1 | 24.7 | 27.2 | 23.2 | 14.6 | 9.4 | 4.0 |
| Average night temperature (°C) | -2.5 | -2.2 | 2.5 | 6.5 | 11.1 | 16.8 | 21.3 | 24.0 | 20.3 | 10.8 | 6.1 | 1.0 |
| Absolute minimum temperature (°C) | -12.1 | -10.4 | -4.3 | 0.6 | 5.1 | 10.1 | 16.7 | 22.2 | 12.8 | 5.7 | 0.2 | -2.8 |
| 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 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.8 | 10.8 | 12.0 | 13.2 | 14.3 | 14.8 | 14.6 | 13.6 | 12.4 | 11.2 | 10.1 | 9.5 |
| 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) | 6.1 | 6.9 | 8.5 | 9.0 | 8.4 | 7.7 | 9.2 | 11.0 | 7.5 | 8.8 | 6.4 | 5.3 |
| Precipitation (mm) | 40 | 75 | 92 | 85 | 160 | 180 | 139 | 115 | 264 | 58 | 126 | 109 |
| Sunny days | 8 | 10 | 15 | 17 | 11 | 7 | 6 | 0 | 3 | 10 | 11 | 6 |
| Rainy days | 12 | 12 | 16 | 13 | 20 | 23 | 25 | 31 | 27 | 21 | 19 | 20 |
| Snow days | 11 | 6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5 |
The best time to visit Koizumi during the most sunny months:
The largest precipitation sum in Koizumi is at