Ulsan weather in January

In January, Ulsan sees average daytime highs of 7°C and overnight lows near -1°C, with 31 mm of precipitation across 4.4 wet days and about 9.9 hours of daylight. It is the 12th-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 7°C through the month. The sky is clear or mostly clear about 56% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 36 min at the start of January to 10 h 12 min by month's end. Set against the rest of the year, January is Ulsan's 2nd-clearest and 1st-windiest month. For the whole year in context, see Ulsan's year-round climate.

Daytime high
12th warmest
Overnight low
-1°
1st coldest
Precipitation
31 mm
4.4 wet days
Daylight
9 h 48 min
7:37 AM – 5:27 PM
Cloud cover
40%
2nd clearest
Wind
14 km/h
1st windiest
Solar energy
2.94 kWh/m²
Travel score
1.0
out of 10
Air quality
Elevated
PM2.5 17 µg/m³ · 2020

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 7°C through the month.

A typical January day in Ulsan reaches about 7°C in the afternoon and slips back to -1°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 2°C and 11°C. Set against its neighbours, January runs about 2°C cooler than December and about 2°C cooler than February.

-10°-5°10°15°151015202531
Avg high (°C)Avg low (°C)
17-1
27-1
37-1
47-1
57-1
67-1
77-1
87-1
97-1
107-1
117-1
127-1
137-1
147-1
157-1
167-1
177-1
187-1
197-1
207-1
217-1
227-1
237-1
247-1
257-1
267-1
277-1
287-1
297-1
307-1
317-1

How January really feels in Ulsan

Once humidity and wind are folded in, January averages 0 days that feel above 32°C and 31 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
31
wind chill below the day's low

The story in January is cold — wind chill drags the overnight "feels like" below the raw low.

Ulsan weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -1°314.40.79.91.0
Feb / 3950.910.72.0
Mar13° / 717.40.511.74.0
Apr18° / 927.6012.96.3
May23° / 13°1007.8013.87.1
Jun25° / 18°1439.1014.46.7
Jul28° / 23°21613.3014.25.3
Aug29° / 23°21314.2013.34.9
Sep25° / 19°17310.4012.26.6
Oct21° / 13°735.1011.17.4
Nov15° / 484.90.110.15.4
Dec / 273.60.39.62.2

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 56% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 13% of January, with mostly cloudy or overcast conditions the remaining 31%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17624
27624
37624
47624
57525
67525
77327
87228
97129
107030
116931
126832
136733
146733
156535
166535
176535
186535
196436
206535
216535
226535
236634
246634
256733
266733
276832
286832
296832
306832
316832

Chance of precipitation in January

Any precipitationSnow

Ulsan gets around 31 mm of rain and snow over 4.4 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 14% and peaks near 16% on the wettest days, and about 1 day brings snow.

0%10%20%30%151015202531
Rain chance (%)Snow chance (%)
1102
2102
3112
4112
5112
6122
7122
8132
9133
10143
11153
12153
13153
14163
15163
16163
17163
18163
19162
20162
21162
22162
23162
24152
25152
26152
27142
28142
29143
30133
31133

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

Most of January feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, January lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in January

Winds average 14 km/h in January, the windiest month of the year.

Across January, daily wind ranges from about 13 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3013light breeze
3113light breeze

Sunrise & sunset in January

DaylightNight

Daylight runs from about 9 h 36 min at the start of January to 10 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 36 minutes over January. Sunrise moves from 7:37 AM to 7:30 AM, and sunset from 5:15 PM to 5:42 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.67:375:15
29.67:375:16
39.77:375:16
49.77:375:17
59.77:375:18
69.77:385:19
79.77:385:19
89.77:385:20
99.77:385:21
109.77:385:22
119.87:375:23
129.87:375:24
139.87:375:25
149.87:375:25
159.87:375:26
169.87:375:27
179.97:365:28
189.97:365:29
199.97:365:30
209.97:365:31
219.97:355:32
2210.07:355:33
2310.07:345:34
2410.07:345:35
2510.07:335:36
2610.17:335:37
2710.17:325:38
2810.17:325:39
2910.17:315:40
3010.27:315:41
3110.27:305:42

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.94 kWh/m².

For context, solar energy here swings from a low near 2.65 kWh/m² to a high of 5.9 kWh/m² in May across the year — January's 2.94 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
12.8Moderate
22.8Moderate
32.8Moderate
42.8Moderate
52.8Moderate
62.8Moderate
72.8Moderate
82.8Moderate
92.8Moderate
102.8Moderate
112.8Moderate
122.8Moderate
132.8Moderate
142.8Moderate
152.9Moderate
162.9Moderate
172.9Moderate
182.9Moderate
192.9Moderate
203.0Moderate
213.0Moderate
223.0Moderate
233.0Moderate
243.1Moderate
253.1Moderate
263.1Moderate
273.2Moderate
283.2Moderate
293.3Moderate
303.3Moderate
313.3Moderate
Planning a trip in January

Hazard calendar for Ulsan

In seasonPeak

In January, Ulsan sits inside its pacific typhoon season. The full year is below, with each hazard's peak months called out.

Ulsan sits in the Pacific typhoon belt; the season peaks July–October.

Ulsan's rainy season runs May–September, when most of the year's rain falls.

Pacific typhoon
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is January a good time to visit Ulsan?

Our two travel scores rate January for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

1.0
Sightseeing
12th-best month of the year
0.0
Beach & pool
10th-best month of the year

January is a weaker month for outdoor sightseeing in Ulsan.

What to pack for Ulsan in January

From January's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In January, Ulsan sees daytime highs around 7°C and nights near -1°C. Pack a warm layer. Worth having: a heavy coat. About 4 days see rain.

a warm layera heavy coat

Sea temperature near Ulsan in January

The nearest coast averages about 15°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 19 km away) is warmest in August at about 26°C and coldest in February near 14°C.

It's comfortable for a long swim from Jun 17 to Nov 9 — about 4.8 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb14Bracing
Mar14Bracing
Apr15Bracing
May17Cool
Jun20Refreshing
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov20Cool
Dec17Cool

UV index in Ulsan in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ulsan peaks around August 17 at about 9 (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.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 17UV 9Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5High
Apr7High
May8Very high
Jun8Very high
Jul9Very high
Aug9Very high
Sep9Very high
Oct5High
Nov4Moderate
Dec2Moderate

Air quality in Ulsan in January

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where January falls, not just the annual average.

Air quality in Ulsan is worst in March — around 21 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (August, 13 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Ulsan's WHO annual average of 17 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2121 µg/m³Aug 1913 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb18Moderate
Mar21Moderate
Apr21Moderate
May20Moderate
Jun17Moderate
Jul14Moderate
Aug13Moderate
Sep14Moderate
Oct16Moderate
Nov18Moderate
Dec15Moderate
Location & terrain

Where is Ulsan?

Ulsan sits at 35.5°N, 129.3°E, 10 m above sea level, in South Korea. The nearest listed city is Ungsang, 20 km away.

GijangGyeongjuMiryangKimhaeYeonilPohang

Topography around Ulsan

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ulsan.

Within 3 km, the terrain around Ulsan has only modest variations in elevation — a maximum elevation change of 136 m around an average of 26 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 752 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,204 m.

The land around Ulsan is covered by artificial surfaces (61%) and trees (30%) within 3 km, trees (55%) within 16 km, and trees (44%) and water (40%) within 80 km.

3 km
136 m
16 km
752 m
80 km
1,204 m
treesgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Ungsang 20 km · Yangsan 34 km · Gijang 34 km · Gyeongju 35 km · Miryang 52 km · Kimhae 52 km · Yeonil 52 km · Pohang 55 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
none 60%Protestant 17%Buddhist 16%Catholic 6%

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 Ulsan (35.5372°, 129.3167°, elevation 10 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).