Ulsan weather in May

In May, Ulsan sees average daytime highs of 23°C and overnight lows near 13°C, with 100 mm of rain across 7.8 wet days and about 13.8 hours of daylight. It is the 5th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 21°C in the first days to 24°C by the end. The sky is clear or mostly clear about 32% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 24 min at the start of May to 14 h 12 min by month's end. Set against the rest of the year, May is Ulsan's 8th-clearest and 11th-windiest month. For the whole year in context, see Ulsan's year-round climate.

Daytime high
23°
5th warmest
Overnight low
13°
8th coldest
Rainfall
100 mm
7.8 wet days
Daylight
13 h 54 min
5:23 AM – 7:15 PM
Cloud cover
59%
8th clearest
Wind
11 km/h
11th windiest
Solar energy
5.9 kWh/m²
Travel score
7.1
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 May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 21°C in the first days to 24°C by the end.

A typical May day in Ulsan reaches about 23°C in the afternoon and slips back to 13°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 27°C. Set against its neighbours, May runs about 4°C warmer than April and about 3°C cooler than June.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12111
22111
32111
42112
52112
62212
72212
82212
92212
102213
112213
122213
132213
142213
152313
162313
172313
182314
192314
202314
212314
222314
232414
242414
252415
262415
272415
282415
292415
302415
312416

How May really feels in Ulsan

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 0 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
0
wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Ulsan weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 5th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 32% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 54%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14852
24951
34852
44753
54753
64753
74654
84654
94654
104654
114555
124555
134654
144654
154654
164654
174654
184654
194654
204654
214654
224654
234654
244753
254654
264654
274654
284654
294555
304555
314456

Chance of precipitation in May

Any precipitation

Ulsan gets around 100 mm of rain over 7.8 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 25% and peaks near 27% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
126
226
326
426
527
627
727
827
927
1027
1127
1227
1327
1427
1526
1626
1726
1826
1926
2025
2125
2224
2324
2424
2523
2623
2722
2822
2922
3022
3122

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 67% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1831241
2821341
3811441
4801541
5801541
6781651
7771751
8761851
9751951
10751951
11742051
12742051
13732151
14712261
15702361
16702361
17692461
18672571
19662671
20642781
21632881
22612991
23603091
245831101
255632111
265533111
275235121
284936131
294638151
304339162
314040172

Wind in May

Winds average 11 km/h in May.

Across May, daily wind ranges from about 10 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
112calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 24 min at the start of May to 14 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 48 minutes over May. Sunrise moves from 5:37 AM to 5:14 AM, and sunset from 7:03 PM to 7:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:377:03
213.55:367:03
313.55:357:04
413.55:347:05
513.55:337:06
613.65:327:07
713.65:317:08
813.65:307:08
913.75:297:09
1013.75:287:10
1113.75:277:11
1213.85:267:12
1313.85:257:13
1413.85:257:13
1513.85:247:14
1613.95:237:15
1713.95:227:16
1813.95:217:17
1913.95:217:17
2014.05:207:18
2114.05:197:19
2214.05:197:20
2314.05:187:20
2414.15:177:21
2514.15:177:22
2614.15:167:23
2714.15:167:23
2814.15:157:24
2914.25:157:25
3014.25:147:26
3114.25:147:26

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.9 kWh/m² — the sunniest month for solar.

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 — May's 5.9 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.7Bright
25.7Bright
35.7Bright
45.7Bright
55.7Bright
65.7Bright
75.7Bright
85.7Bright
95.7Bright
105.8Bright
115.8Bright
125.8Bright
135.8Bright
145.8Bright
155.8Bright
165.9Bright
175.9Bright
185.9Bright
195.9Bright
206.0Bright
216.0Bright
226.0Intense
236.0Intense
246.0Intense
256.1Intense
266.1Intense
276.1Intense
286.1Intense
296.1Intense
306.1Intense
316.1Intense
Planning a trip in May

Hazard calendar for Ulsan

In seasonPeak

In May, Ulsan sits inside its pacific typhoon and rainy season 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 May a good time to visit Ulsan?

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

7.1
Sightseeing
2nd-best month of the year
5.3
Beach & pool
5th-best month of the year

May is one of the better times to visit Ulsan for general sightseeing.

What to pack for Ulsan in May

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

In May, Ulsan sees daytime highs around 23°C and nights near 13°C. Worth packing: light clothes and sun protection. About 8 days see rain.

light clothessun protection

Sea temperature near Ulsan in May

The nearest coast averages about 17°C in May — 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — enough to warrant sun protection. 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 May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May 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
May 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).