Jeju weather in May

In May, Jeju sees average daytime highs of 19°C and overnight lows near 15°C, with 109 mm of rain across 8.8 wet days and about 13.7 hours of daylight. It is the 6th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 17°C in the first days to 20°C by the end. The sky is clear or mostly clear about 33% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 18 min at the start of May to 14 hours by month's end. Set against the rest of the year, May is Jeju's 5th-clearest and 11th-windiest month. For the whole year in context, see Jeju's year-round climate.

Daytime high
19°
6th warmest
Overnight low
15°
7th coldest
Rainfall
109 mm
8.8 wet days
Daylight
13 h 42 min
5:38 AM – 7:22 PM
Cloud cover
59%
5th clearest
Wind
14 km/h
11th windiest
Solar energy
5.73 kWh/m²
Travel score
6.2
out of 10

Jeju is city in South Korea.

Density
500/km²
people per km²

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 17°C in the first days to 20°C by the end.

A typical May day in Jeju reaches about 19°C in the afternoon and slips back to 15°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 21°C. Set against its neighbours, May runs about 4°C warmer than April and about 3°C cooler than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
11713
21713
31714
41714
51814
61814
71814
81814
91814
101814
111814
121815
131815
141815
151815
161915
171915
181915
191915
201915
211916
221916
231916
241916
252016
262016
272016
282016
292017
302017
312017

How May really feels in Jeju

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.

Jeju weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 7311.62.6101.1
Feb / 649.31.710.81.5
Mar11° / 9510.30.411.72.9
Apr15° / 11°1028.9012.84.6
May19° / 15°1098.8013.76.2
Jun22° / 19°18911.6014.26.1
Jul26° / 24°18412.10146.2
Aug27° / 25°16813.7013.25.9
Sep24° / 22°16511.1012.26.7
Oct20° / 17°796.8011.26.9
Nov15° / 12°708.8010.34.7
Dec10° / 68111.19.82.3

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 12% of May, with mostly cloudy or overcast conditions the remaining 55%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14951
24852
34852
44852
54753
64753
74654
84555
94555
104456
114357
124357
134357
144357
154456
164357
174357
184357
194357
204258
214456
224456
234456
244456
254456
264555
274555
284654
294654
304654
314654

Chance of precipitation in May

Any precipitation

Jeju gets around 109 mm of rain over 8.8 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 28% and peaks near 31% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
130
230
330
430
531
631
731
831
931
1031
1130
1230
1330
1429
1529
1629
1728
1828
1928
2027
2127
2227
2326
2426
2526
2625
2725
2825
2925
3025
3125

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 41% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1652960
2642970
3633070
4613180
5603280
6573391
7563491
85534101
95335111
105236111
115136121
125037131
134837141
144638151
154439161
164240171
174040181
183841191
193642211
203442221
213243231
223043252
232844262
242744282
252544302
262343322
272143343
281942363
291741384
301540405
311438436

Wind in May

Winds average 14 km/h in May.

Across May, daily wind ranges from about 12 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2912light breeze
3012light breeze
3112light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 18 min at the start of May to 14 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over May. Sunrise moves from 5:52 AM to 5:30 AM, and sunset from 7:11 PM to 7:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:527:11
213.35:517:11
313.45:507:12
413.45:497:13
513.45:487:14
613.55:477:14
713.55:467:15
813.55:457:16
913.55:447:17
1013.65:437:17
1113.65:427:18
1213.65:417:19
1313.75:417:20
1413.75:407:21
1513.75:397:21
1613.75:387:22
1713.85:387:23
1813.85:377:24
1913.85:367:24
2013.85:367:25
2113.85:357:26
2213.95:347:26
2313.95:347:27
2413.95:337:28
2513.95:337:28
2613.95:327:29
2714.05:327:30
2814.05:317:31
2914.05:317:31
3014.05:317:32
3114.05:307:32

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.73 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.09 kWh/m² to a high of 5.73 kWh/m² in May across the year — May's 5.73 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.6Bright
35.6Bright
45.6Bright
55.6Bright
65.6Bright
75.6Bright
85.6Bright
95.6Bright
105.7Bright
115.7Bright
125.7Bright
135.7Bright
145.7Bright
155.7Bright
165.7Bright
175.7Bright
185.7Bright
195.8Bright
205.8Bright
215.8Bright
225.8Bright
235.8Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
315.8Bright
Planning a trip in May

Hazard calendar for Jeju

In seasonPeak

In May, Jeju sits inside its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.

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

Jeju's rainy season runs March–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 Jeju?

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

6.2
Sightseeing
3rd-best month of the year
2.4
Beach & pool
6th-best month of the year

May is a reasonable time to visit Jeju for sightseeing.

What to pack for Jeju in May

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

In May, Jeju sees daytime highs around 19°C and nights near 15°C. Worth packing: rain gear and sun protection. About 9 days see rain.

rain gearsun protection

Sea temperature near Jeju in May

The nearest coast averages about 16°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 16 km away) is warmest in August at about 27°C and coldest in March near 14°C.

It's comfortable for a long swim from Jun 18 to Nov 4 — about 4.6 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Cool
Feb14Bracing
Mar14Bracing
Apr14Bracing
May16Cool
Jun20Cool
Jul24Refreshing
Aug27Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec17Cool

UV index in Jeju in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Jeju peaks around July 16 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJul 16UV 10Dec 21UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7High
May8Very high
Jun8Very high
Jul10Very high
Aug8Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Jeju 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 Jeju is worst in March — around 30 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (July, 13 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2130 µg/m³Jul 2413 µg/m³
PM2.5 (µg/m³)Level
Jan21Moderate
Feb25Moderate
Mar30Moderate
Apr29Moderate
May23Moderate
Jun18Moderate
Jul13Moderate
Aug13Moderate
Sep14Moderate
Oct15Moderate
Nov18Moderate
Dec16Moderate
Location & terrain

Where is Jeju?

Jeju sits at 33.5°N, 126.5°E, 19 m above sea level, in South Korea. The nearest listed city is Ido-dong, 1.0 km away.

Haenam

Topography around Jeju

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

Within 3 km, the terrain around Jeju has only modest variations in elevation — a maximum elevation change of 141 m around an average of 43 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,836 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,915 m.

The land around Jeju is covered by artificial surfaces (51%) and water (29%) within 3 km, water (47%) and trees (36%) within 16 km, and water (88%) within 80 km.

3 km
141 m
16 km
1,836 m
80 km
1,915 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Ido-dong 1.0 km · Ora-dong 3.0 km · Seodong 4.0 km · Ara-dong 5.0 km · Tallang-dong 5.0 km · Gaigeturi 20 km · Seogwipo 29 km · Haenam 118 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 Jeju (33.5097°, 126.5219°, elevation 19 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).