Sejong in Winter
In winter (December, January and February), Sejong sees average daytime highs around 5°C and overnight lows near -4°C, with 76 mm of precipitation over about 13 wet days across the season. It is the coldest season of the year and the driest season of the year.
Across winter, daytime highs hold fairly steady around 5°C. The sky is clear or mostly clear about 35% of the time across winter, and the air most often feels dry.
Winter is Sejong's weakest season of the year to visit on our travel score. For the whole year in context, see Sejong's year-round climate.
- Avg daytime high
- 5°C
- coldest season of the year
- Avg overnight low
- -4°C
- Precipitation
- 76 mm
- 13 wet days
- Avg wind
- 9 km/h
- Travel score
- 0.4
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Sejong in Winter
Across winter, daytime highs hold fairly steady around 5°C.
A typical winter day in Sejong reaches about 5°C and drops to -4°C overnight. The warmest of the three months is February, the coolest January.
How winter really feels in Sejong
Once humidity and wind are folded in, winter brings about 0 days that feel above 32°C and 90 that feel at or below 0°C.
The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.
Sejong weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 4° / -5° | 22 | 4.3 | 2.2 | 9.8 | 0.0 |
| Feb | 6° / -3° | 30 | 4.3 | 1.5 | 10.6 | 0.7 |
| Mar | 12° / 1° | 49 | 6.7 | 1.1 | 11.7 | 3.6 |
| Apr | 19° / 7° | 79 | 7.4 | 0 | 12.9 | 6.5 |
| May | 24° / 13° | 86 | 7.5 | 0 | 13.9 | 7.2 |
| Jun | 28° / 18° | 122 | 8.5 | 0 | 14.5 | 6.1 |
| Jul | 29° / 22° | 256 | 16.1 | 0 | 14.2 | 4.5 |
| Aug | 30° / 22° | 226 | 15 | 0 | 13.4 | 4.4 |
| Sep | 26° / 17° | 143 | 8.5 | 0 | 12.2 | 6.8 |
| Oct | 20° / 10° | 58 | 4.8 | 0 | 11.1 | 7.4 |
| Nov | 13° / 3° | 43 | 5.9 | 0.2 | 10 | 4.0 |
| Dec | 6° / -3° | 23 | 4.5 | 1.4 | 9.5 | 0.5 |
Cloud cover in Winter
The sky is clear or mostly clear about 35% of the time across winter.
Chance of precipitation in Winter
Sejong gets around 76 mm of rain and snow over 13 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 9 km/h across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 42 min in early December to 11 h 06 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 2.8 kWh/m².
Hazard calendar for Sejong
None of Sejong's seasonal hazards peak in winter. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do.
Sejong's rainy season runs June–September, when most of the year's rain falls.
Is winter a good time to visit Sejong?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Sejong.
What to pack for Sejong in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Sejong sees daytime highs around 5°C and nights near -4°C. Pack a warm layer and a heavy coat. About 13 days see rain.
UV index in Sejong in Winter
Clear-sky midday UV across winter averages around 2. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Sejong peaks around August 14 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 6 | 7 | 7 | 8 | 8 | 8 | 5 | 3 | 2 |
| Level | Moderate | Moderate | Moderate | High | High | Very high | Very high | Very high | Very high | High | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 3 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 7 | High |
| Jun | 7 | Very high |
| Jul | 8 | Very high |
| Aug | 8 | Very high |
| Sep | 8 | Very high |
| Oct | 5 | High |
| Nov | 3 | Moderate |
| Dec | 2 | Low |
Air quality in Sejong in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in Sejong is worst in March — around 80 µg/m³ PM2.5 (unhealthy), about 1.8× the cleanest month (July, 45 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 69 | 72 | 80 | 65 | 58 | 54 | 45 | 45 | 56 | 67 | 72 | 65 |
| Level | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Poor | Poor | Poor | Unhealthy | Unhealthy | Unhealthy | Unhealthy |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 69 | Unhealthy |
| Feb | 72 | Unhealthy |
| Mar | 80 | Unhealthy |
| Apr | 65 | Unhealthy |
| May | 58 | Unhealthy |
| Jun | 54 | Poor |
| Jul | 45 | Poor |
| Aug | 45 | Poor |
| Sep | 56 | Unhealthy |
| Oct | 67 | Unhealthy |
| Nov | 72 | Unhealthy |
| Dec | 65 | Unhealthy |
Where is Sejong?
Sejong sits at 36.6°N, 127.3°E, 49 m above sea level, in South Korea. The nearest listed city is Cheongju-si, 18 km away.
Topography around Sejong
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Sejong.
Within 3 km, the terrain around Sejong has only modest variations in elevation — a maximum elevation change of 148 m around an average of 39 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 445 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,213 m.
The land around Sejong is covered by cropland (43%), artificial surfaces (28%) and trees (21%) within 3 km, trees (54%) and cropland (22%) within 16 km, and trees (62%) and cropland (23%) within 80 km.
South Korea travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type C / F
- 220 V · 60 Hz
- Prices
- ≈ 57% of US
- price level, 2025
- GDP per capita
- $36,227
- 2025
- Happiness
- 6.0 / 10
- World Happiness, 2025
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 0.5
- per 100k, 2023
- Road deaths
- 8.6
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Moderate
- EF EPI 522
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Sejong (36.5924°, 127.2922°, elevation 49 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.