Climate averages 1991–2020
Sejong weather
in December.
A cold, fairly dry month: the 11th warmest and the 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Sejong: daytime highs average 4.8°C and nights cool to about -2.9°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 23 mm of rain on roughly 5 days, which makes December a fairly dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 43 min on an average December day.
The nearest other city in this atlas is Cheongju-si (18 km away). In December its highs average 4.8°C, about as warm as Sejong, with 24 mm of rain.
Among the 79 cities listed in South Korea, Sejong ranks joint 45th of 79 for the warmest December highs and joint 15th of 79 for the driest December (rainfall, lowest first). The mean December high of those 79 cities is 5.6°C; Sejong is 0.8°C cooler than that mean.
From December to January, average highs fall by 1.9°C to 2.9°C, and monthly rainfall falls from 23 mm to 22 mm.
The annual picture
December 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
Sejong climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.9°C-4.6°C | -4.6°C | 22 | 4.3 | 10.010 h |
| February | 5.7°C-3.2°C | -3.2°C | 31 | 4.4 | 10.811 h |
| March | 11.3°C0.6°C | 0.6°C | 49 | 6.7 | 11.912 h |
| April | 18.1°C6.4°C | 6.4°C | 78 | 7.4 | 13.113 h |
| May | 23.6°C12.3°C | 12.3°C | 86 | 7.5 | 14.114 h |
| June | 27.8°C17.8°C | 17.8°C | 122 | 8.5 | 14.615 h |
| July | 28.9°C21.7°C | 21.7°C | 256 | 16.1 | 14.414 h |
| August | 29.3°C22.3°C | 22.3°C | 226 | 15.0 | 13.614 h |
| September | 25.2°C16.9°C | 16.9°C | 143 | 8.5 | 12.412 h |
| October | 19.4°C9.9°C | 9.9°C | 58 | 4.8 | 11.311 h |
| November | 11.9°C3.0°C | 3.0°C | 43 | 5.9 | 10.310 h |
| December, selected | 4.8°C-2.9°C | -2.9°C | 23 | 4.5 | 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
December in nearby cities
- Cheongju-si in DecemberSouth Korea · 18 kmHigh 4.8°C · Low -2.9°C · 24 mm rain
- Gongju in DecemberSouth Korea · 21 kmHigh 5.3°C · Low -2.1°C · 24 mm rain
- Cheonan in DecemberSouth Korea · 27 kmHigh 4.7°C · Low -2.9°C · 23 mm rain
- Daejeon in DecemberSouth Korea · 28 kmHigh 5.3°C · Low -2.4°C · 25 mm rain
- Asan in DecemberSouth Korea · 33 kmHigh 4.6°C · Low -2.8°C · 23 mm rain
- Pyeongtaek in DecemberSouth Korea · 48 kmHigh 4.3°C · Low -3.2°C · 23 mm rain
- Hongseong in DecemberSouth Korea · 56 kmHigh 5.1°C · Low -1.9°C · 24 mm rain
- Osan in DecemberSouth Korea · 65 kmHigh 4.2°C · Low -3.6°C · 23 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 Sejong) is explained once on the Sejong year overview and on the Sources, method and limits page.