Jeju City climate

Name: Jeju City
Address: KR

Jeju City is warmest in August, with average highs of 29 °C, and coldest in January, when nights average 4.4 °C. June is the wettest month (199 mm) and February the driest (66 mm). Figures are 1991–2020 climate normals.

Across a full year Jeju City averages 1,456 mm of rain, 82 days above 25 °C and 2 days below freezing.

South Korea · population 488,844 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month August 29 °C
Coldest month January 4.4 °C
Driest month February 66 mm
Wettest month June 199 mm
Least cloud October 50 % cloud
Hottest on record August 34 °C
Coldest on record January -4.3 °C
Warmest sea August 27 °C

What to expectJeju City through the year

Jeju City has a clear annual cycle: average daily highs run from 7.8 °C in January to 29 °C in August, a swing of 21 °C in mean temperature across the year.

Counted across a normal year, 82 days a year reach 25 °C, 14 of them reach 30 °C, 2 nights drop below freezing. The warmest reading in the 1991–2020 record is 34 °C, in August.

Rain is strongly seasonal. June averages 199 mm against 66 mm in February — 3.0 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Jeju City is warmest in August at 27 °C and coldest in March at 14 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	7.8 °C	77 mm	78 %
February	8.8 °C	66 mm	71 %
March	12.0 °C	97 mm	63 %
April	16.3 °C	106 mm	61 %
May	20.3 °C	110 mm	63 %
June	23.6 °C	199 mm	73 %
July	27.7 °C	194 mm	69 %
August	28.8 °C	185 mm	61 %
September	25.3 °C	186 mm	58 %
October	20.6 °C	92 mm	50 %
November	15.5 °C	71 mm	58 %
December	10.2 °C	73 mm	69 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C	Days below 0 °C
January	7.8 °C	4.4 °C	6.2 °C	19.9 °C	-4.3 °C	0	0	1
February	8.8 °C	4.9 °C	6.9 °C	20.5 °C	-4.0 °C	0	0	1
March	12.0 °C	7.6 °C	9.8 °C	24.1 °C	-0.1 °C	0	0	0
April	16.3 °C	11.7 °C	13.9 °C	25.2 °C	2.6 °C	0	0	0
May	20.3 °C	15.8 °C	18.0 °C	29.9 °C	8.2 °C	1	0	0
June	23.6 °C	19.9 °C	21.7 °C	29.4 °C	14.2 °C	7	0	0
July	27.7 °C	24.4 °C	25.9 °C	33.7 °C	18.5 °C	27	4	0
August	28.8 °C	25.5 °C	27.1 °C	34.3 °C	19.7 °C	30	9	0
September	25.3 °C	22.1 °C	23.6 °C	30.3 °C	15.2 °C	17	0	0
October	20.6 °C	17.1 °C	18.8 °C	27.6 °C	7.8 °C	1	0	0
November	15.5 °C	11.6 °C	13.6 °C	23.9 °C	2.6 °C	0	0	0
December	10.2 °C	6.6 °C	8.4 °C	21.3 °C	-0.8 °C	0	0	0

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	77 mm	11	10 h/day	78 %	69 %	28 km/h	15.2 °C
February	66 mm	10	11 h/day	71 %	69 %	27 km/h	14.0 °C
March	97 mm	10	12 h/day	63 %	71 %	26 km/h	13.7 °C
April	106 mm	9	13 h/day	61 %	75 %	23 km/h	14.4 °C
May	110 mm	9	14 h/day	63 %	80 %	20 km/h	16.3 °C
June	199 mm	12	14 h/day	73 %	87 %	19 km/h	19.8 °C
July	194 mm	13	14 h/day	69 %	88 %	20 km/h	23.9 °C
August	185 mm	14	13 h/day	61 %	85 %	20 km/h	26.6 °C
September	186 mm	12	12 h/day	58 %	80 %	23 km/h	24.7 °C
October	92 mm	7	11 h/day	50 %	73 %	24 km/h	21.8 °C
November	71 mm	9	10 h/day	58 %	71 %	24 km/h	18.9 °C
December	73 mm	11	9.9 h/day	69 %	69 %	28 km/h	16.7 °C

How Jeju City compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Jeju City	29 °C	4.4 °C	1,456 mm	82
Seogwipo · South Korea	29 °C	3.9 °C	1,719 mm	97
Mokpo · South Korea	28 °C	-0.3 °C	1,244 mm	65
Yeosu · South Korea	28 °C	-0.2 °C	1,406 mm	67
Suncheon · South Korea	29 °C	-2.2 °C	1,520 mm	106
Gwangju · South Korea	29 °C	-3.0 °C	1,246 mm	107
Gwangyang · South Korea	29 °C	-2.5 °C	1,527 mm	95

Planning a trip? See the best time to visit Jeju City.

QuestionsCommon questions about Jeju City’s climate

When is the best time to visit Jeju City?

That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, October sit closest to 20 °C on average, August is the warmest month and February the driest. The month-by-month table above has the full picture.

How hot does Jeju City get?

In August, the warmest month, daily highs average 29 °C. About 14 days a year pass 30 °C. The highest value in the 1991–2020 record is 34 °C.

How cold does it get in winter?

Nights average 4.4 °C in January, the coldest month. A normal year has 2 nights below freezing.

Which month is wettest in Jeju City?

June, averaging 199 mm over 12 days with rain. The driest month is February with 66 mm. The year as a whole averages 1,456 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Jeju City rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.