Incheon climate

Name: Incheon
Address: KR

Incheon is warmest in August, with average highs of 28 °C, and coldest in January, when nights average -6.1 °C. July is the wettest month (300 mm) and January the driest (18 mm). Figures are 1991–2020 climate normals.

Across a full year Incheon averages 1,152 mm of rain, 71 days above 25 °C and 102 days below freezing.

South Korea · population 3,015,482 · 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 28 °C
Coldest month January -6.1 °C
Driest month January 18 mm
Wettest month July 300 mm
Least cloud October 44 % cloud
Hottest on record July 35 °C
Coldest on record January -20 °C
Warmest sea August 24 °C

What to expectIncheon through the year

Incheon has a clear annual cycle: average daily highs run from 1.3 °C in January to 28 °C in August, a swing of 27 °C in mean temperature across the year.

Counted across a normal year, 71 days a year reach 25 °C, 6 of them reach 30 °C, 102 nights drop below freezing. The warmest reading in the 1991–2020 record is 35 °C, in July.

Rain is strongly seasonal. July averages 300 mm against 18 mm in January — 16 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Incheon is warmest in August at 24 °C and coldest in February at 4.0 °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	1.3 °C	18 mm	47 %
February	3.6 °C	25 mm	46 %
March	8.5 °C	35 mm	48 %
April	14.4 °C	65 mm	51 %
May	19.6 °C	93 mm	55 %
June	23.9 °C	130 mm	65 %
July	26.4 °C	300 mm	73 %
August	27.5 °C	245 mm	64 %
September	24.0 °C	119 mm	55 %
October	18.1 °C	53 mm	44 %
November	10.5 °C	47 mm	46 %
December	3.4 °C	23 mm	45 %

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	1.3 °C	-6.1 °C	-2.4 °C	11.9 °C	-20.3 °C	0	0	29
February	3.6 °C	-4.0 °C	-0.4 °C	15.2 °C	-19.9 °C	0	0	25
March	8.5 °C	0.5 °C	4.3 °C	19.1 °C	-6.3 °C	0	0	14
April	14.4 °C	6.5 °C	10.2 °C	24.3 °C	-1.8 °C	0	0	0
May	19.6 °C	12.1 °C	15.6 °C	28.4 °C	5.7 °C	1	0	0
June	23.9 °C	17.4 °C	20.4 °C	32.3 °C	11.9 °C	9	0	0
July	26.4 °C	21.6 °C	23.7 °C	34.6 °C	16.0 °C	23	2	0
August	27.5 °C	22.5 °C	24.8 °C	34.6 °C	15.7 °C	27	4	0
September	24.0 °C	17.5 °C	20.6 °C	31.1 °C	9.1 °C	10	0	0
October	18.1 °C	10.6 °C	14.2 °C	26.6 °C	-1.1 °C	0	0	0
November	10.5 °C	3.2 °C	6.8 °C	22.2 °C	-10.8 °C	0	0	8
December	3.4 °C	-3.8 °C	-0.2 °C	14.1 °C	-15.4 °C	0	0	26

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	18 mm	4	9.9 h/day	47 %	62 %	17 km/h	5.5 °C
February	25 mm	4	11 h/day	46 %	64 %	18 km/h	4.0 °C
March	35 mm	5	12 h/day	48 %	70 %	19 km/h	4.9 °C
April	65 mm	7	13 h/day	51 %	73 %	20 km/h	7.9 °C
May	93 mm	8	14 h/day	55 %	78 %	18 km/h	11.9 °C
June	130 mm	8	15 h/day	65 %	83 %	16 km/h	16.6 °C
July	300 mm	15	15 h/day	73 %	88 %	17 km/h	20.7 °C
August	245 mm	14	14 h/day	64 %	85 %	16 km/h	23.6 °C
September	119 mm	8	12 h/day	55 %	78 %	15 km/h	23.2 °C
October	53 mm	5	11 h/day	44 %	72 %	16 km/h	19.7 °C
November	47 mm	7	10 h/day	46 %	71 %	17 km/h	14.9 °C
December	23 mm	5	9.6 h/day	45 %	65 %	18 km/h	9.5 °C

How Incheon 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
Incheon	28 °C	-6.1 °C	1,152 mm	71
Bucheon-si · South Korea	28 °C	-6.4 °C	1,153 mm	83
Anyang-si · South Korea	28 °C	-6.1 °C	1,209 mm	84
Gunpo · South Korea	28 °C	-6.1 °C	1,139 mm	85
Goyang-si · South Korea	28 °C	-7.2 °C	1,203 mm	91
Seoul · South Korea	29 °C	-7.1 °C	1,206 mm	97
Hwaseong-si · South Korea	27 °C	-4.4 °C	1,224 mm	68

Planning a trip? See the best time to visit Incheon.

QuestionsCommon questions about Incheon’s climate

When is the best time to visit Incheon?

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

How hot does Incheon get?

In August, the warmest month, daily highs average 28 °C. About 6 days a year pass 30 °C. The highest value in the 1991–2020 record is 35 °C.

How cold does it get in winter?

Nights average -6.1 °C in January, the coldest month. A normal year has 102 nights below freezing.

Which month is wettest in Incheon?

July, averaging 300 mm over 15 days with rain. The driest month is January with 18 mm. The year as a whole averages 1,152 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 Incheon 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
Data point: 37.456°, 126.705° (the coordinates the reanalysis values are taken for)
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.