Average annual temperature is 13.6 °C
Absolute maximum temperature: 34.1 °C
Absolute minimum temperature: -15.2 °C
Number of sunny days: 175 days
Number of rainy days: 176 days
Number of snow days: 14 days
Look at detailed online map of Osan
* Weather data for Osan South Korea is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 15.6 | 13.4 | 22.8 | 25.4 | 30.8 | 32.7 | 32.7 | 34.1 | 30.3 | 22.3 | 24.3 | 17.4 |
| Average daytime temperature (°C) | 4.0 | 7.4 | 15.8 | 18.4 | 23.0 | 27.9 | 29.3 | 30.4 | 26.3 | 19.3 | 11.5 | 6.2 |
| Average temperature (°C) | -0.3 | 2.2 | 9.5 | 12.7 | 18.0 | 22.6 | 25.5 | 26.1 | 22.1 | 14.2 | 7.0 | 2.5 |
| Average night temperature (°C) | -4.2 | -1.5 | 4.3 | 7.7 | 13.2 | 18.2 | 22.3 | 22.5 | 18.6 | 9.9 | 2.8 | -1.0 |
| Absolute minimum temperature (°C) | -15.2 | -6.3 | -3.8 | 0.5 | 3.7 | 13.8 | 19.8 | 17.9 | 13.1 | 4.8 | -6.8 | -11.9 |
| 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) | 10.0 | 10.9 | 12.0 | 13.1 | 14.1 | 14.6 | 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) | 7.2 | 7.4 | 8.9 | 7.9 | 8.2 | 10.0 | 7.3 | 9.4 | 7.4 | 8.8 | 7.3 | 5.8 |
| Precipitation (mm) | 37 | 12 | 40 | 101 | 115 | 159 | 496 | 310 | 210 | 17 | 63 | 98 |
| Sunny days | 17 | 19 | 22 | 14 | 17 | 11 | 5 | 5 | 10 | 22 | 17 | 16 |
| Rainy days | 7 | 8 | 9 | 16 | 14 | 19 | 26 | 26 | 20 | 9 | 13 | 9 |
| Snow days | 7 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 6 |
The largest precipitation sum in Osan is at