Climate averages 1991–2020
Osan weather
in August.
A hot, very wet month: the warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Osan: daytime highs average 28.8°C and nights cool to about 22.3°C. By daytime temperature it is the warmest month of the year.
Expect about 231 mm of rain on roughly 14 days, which makes August a very wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 35 min on an average August day.
The nearest other city in this atlas is Suwon (16 km away). In August its highs average 28.4°C, about as warm as Osan, with 231 mm of rain.
Among the 79 cities listed in South Korea, Osan ranks joint 33rd of 79 for the warmest August highs and joint 44th of 79 for the driest August (rainfall, lowest first). The mean August high of those 79 cities is 28.6°C; Osan is 0.2°C warmer than that mean.
From August to September, average highs fall by 3.9°C to 24.8°C, and monthly rainfall falls from 231 mm to 124 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Osan climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.2°C-5.5°C | -5.5°C | 20 | 3.8 | 9.910 h |
| February | 4.9°C-3.8°C | -3.8°C | 27 | 4.1 | 10.811 h |
| March | 10.2°C0.1°C | 0.1°C | 39 | 6.1 | 11.912 h |
| April | 16.8°C5.7°C | 5.7°C | 69 | 7.1 | 13.113 h |
| May | 22.2°C11.6°C | 11.6°C | 88 | 7.1 | 14.114 h |
| June | 26.5°C17.1°C | 17.1°C | 118 | 7.6 | 14.715 h |
| July | 28.2°C21.6°C | 21.6°C | 279 | 15.3 | 14.414 h |
| August, selected | 28.8°C22.3°C | 22.3°C | 231 | 14.0 | 13.614 h |
| September | 24.8°C16.9°C | 16.9°C | 124 | 7.8 | 12.512 h |
| October | 18.9°C9.7°C | 9.7°C | 55 | 5.2 | 11.311 h |
| November | 11.3°C2.6°C | 2.6°C | 47 | 7.3 | 10.210 h |
| December | 4.2°C-3.6°C | -3.6°C | 23 | 5.1 | 9.710 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- Suwon in AugustSouth Korea · 16 kmHigh 28.4°C · Low 22.1°C · 231 mm rain
- Pyeongtaek in AugustSouth Korea · 18 kmHigh 28.9°C · Low 22.4°C · 232 mm rain
- Hwaseong-si in AugustSouth Korea · 23 kmHigh 27.3°C · Low 22.8°C · 239 mm rain
- Ansan-si in AugustSouth Korea · 29 kmHigh 28.0°C · Low 22.6°C · 239 mm rain
- Anyang-si in AugustSouth Korea · 30 kmHigh 28.0°C · Low 22.3°C · 258 mm rain
- Seongnam-si in AugustSouth Korea · 32 kmHigh 28.4°C · Low 21.9°C · 277 mm rain
- Gwangju, South Korea in AugustSouth Korea · 33 kmHigh 29.0°C · Low 22.1°C · 277 mm rain
- Icheon-si in AugustSouth Korea · 36 kmHigh 28.8°C · Low 21.8°C · 252 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Osan) is explained once on the Osan year overview and on the Sources, method and limits page.
Suwon lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.