Ulsan weather in December
Temperature, sea and sunshine in December: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in December
Fair
Best time to visit: April – June, September – October
What is the weather like in Ulsan in December?
In December, Ulsan is cold: daytime highs average 8 °C, and nights cool down to about 1 °C. The sea averages 17.0 °C – bracing, so a wetsuit helps for longer swims. Expect around 6 hours of sunshine a day. Rain is rare: about 3 days bring 27 mm in total. All in all, December is a so-so month for a holiday in Ulsan.
December compared
How the weather changes from November to January. Tap a month to open it.
| NovemberNov | DecemberDec | JanuaryJan | |
|---|---|---|---|
| Score | 71 | 41 | 40 |
| Day | 14° | 8° | 6° |
| Night | 8° | 1° | −1° |
| Sea | 20° | 17° | 15° |
| Sun | 6 h | 6 h | 6 h |
| Rain days | 5 | 3 | 4 |
More details for December
- Daylight
- 9 h 47 min07:25 – 17:11
- UV index
- 2 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 19 km/haverage daily peakAll months
- Cloud cover
- 34 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snow
- Time zone
- UTC+9Asia/Seoul
How the score comes together
- Temperatureweight 50 %0 %
- Sunshineweight 20 %55 %
- Few rainy daysweight 30 %100 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in December
- Warm jacket
Ulsan in December: quick answers
Is Ulsan hot in December?
No. In December, Ulsan is cold: daytime highs average 8 °C and nights drop to about 1 °C.
Can you swim in Ulsan in December?
Only if you don't mind cold water: in December the sea averages just 17.0 °C. Comfortable swimming is possible from June to October.
Does it rain much in Ulsan in December?
Rain is rare: about 3 days bring 27 mm in total.
Ulsan month by month
The whole year in UlsanAll destinations: South KoreaWhere to go in DecemberSea temperature in December
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences