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Monthly climate in Koesan, South Korea

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Koesan features a humid continental climate (Dwa). Temperatures typically range between -2 °C (29 °F) and 26 °C (79 °F) through the year, but rarely can drop to -20 °C (-3 °F) or can rise to as high as 38 °C (100 °F). The average annual precipitation amounts to about 1169 mm (46.0 inches) and receives 90 rainy days on the 1 mm (0.04 inches) threshold annually. Koesan enjoys an average of 3119 hours of sunshine throughout the year, and daylight varies from 9 hours 40 minutes to 14 hours 37 minutes per day.

Monthly average temperatures in Koesan, South Korea

The warmest months in Koesan are June, July and August, with daily mean temperatures ranging from 22 to 26 °C (72 - 79 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -2 to 0 °C (29 - 33 °F) throughout the day. On average each year, Koesan experiences 95 days above 25 °C (77.0 °F) and 93 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Koesan. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum12°C
(54°F)		20°C
(69°F)		22°C
(73°F)		28°C
(82°F)		32°C
(89°F)		34°C
(93°F)		36°C
(96°F)		38°C
(100°F)		29°C
(85°F)		30°C
(86°F)		21°C
(69°F)		13°C
(56°F)
Mean maximum10°C
(50°F)		14°C
(57°F)		20°C
(69°F)		26°C
(80°F)		30°C
(86°F)		31°C
(89°F)		33°C
(92°F)		35°C
(95°F)		29°C
(84°F)		26°C
(80°F)		20°C
(68°F)		12°C
(53°F)
Average high3°C
(38°F)		5°C
(42°F)		13°C
(55°F)		18°C
(65°F)		23°C
(75°F)		27°C
(81°F)		29°C
(84°F)		30°C
(86°F)		25°C
(77°F)		20°C
(67°F)		13°C
(55°F)		5°C
(40°F)
Daily mean-2°C
(29°F)		0°C
(33°F)		7°C
(45°F)		12°C
(55°F)		18°C
(64°F)		22°C
(72°F)		25°C
(78°F)		26°C
(79°F)		21°C
(69°F)		14°C
(58°F)		7°C
(45°F)		-0°C
(32°F)
Average low-6°C
(21°F)		-4°C
(24°F)		2°C
(35°F)		6°C
(44°F)		12°C
(54°F)		17°C
(63°F)		22°C
(72°F)		23°C
(73°F)		17°C
(62°F)		10°C
(49°F)		2°C
(36°F)		-4°C
(25°F)
Mean minimum-14°C
(7°F)		-11°C
(12°F)		-4°C
(24°F)		-0°C
(31°F)		6°C
(42°F)		13°C
(56°F)		18°C
(64°F)		18°C
(64°F)		11°C
(52°F)		1°C
(35°F)		-4°C
(25°F)		-13°C
(9°F)
Minimum-20°C
(-3°F)		-15°C
(5°F)		-7°C
(19°F)		-3°C
(28°F)		3°C
(37°F)		11°C
(52°F)		16°C
(61°F)		15°C
(59°F)		8°C
(47°F)		-0°C
(32°F)		-6°C
(22°F)		-14°C
(6°F)

Compare climate in Koesan with other places

Compare temperature, precipitation, sunshine, UV index in Koesan, South Korea with other places around the world.

Monthly average precipitation in Koesan, South Korea

Koesan usually has the most precipitation in July, August and September, with an average of 13 rainy days and 214 mm (8.4 inches) of precipitation per month. The driest months in Koesan are January, February and December. On average, 27 mm (1.1 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Koesan. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)22 (0.9)33 (1.3)67 (2.7)74 (2.9)98 (3.9)89 (3.5)239 (9.4)241 (9.5)163 (6.4)73 (2.9)44 (1.7)25 (1.0)
Average precipitation days (≥ 1 mm)34669816159653

Monthly sunshine hours in Koesan, South Korea

The sunniest months in Koesan are April, May and June, when the sun shines an average of 9 hours 48 minutes a day. Least sunny months in Koesan: January, November and December receive an average of 7 hours 11 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Koesan. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours195237275281305306271269249260229236
Mean daily daylight hours9h 56m10h 49m11h 57m13h 8m14h 7m14h 37m14h 22m13h 30m12h 23m11h 13m10h 11m9h 40m

Solar UV radiation in Koesan, South Korea

Koesan experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 11 - 11, which corresponds to the Extreme category of sun exposure. January, February and December are in the Moderate exposure category. In these months, the maximum values of the UV index do not exceed 4. For more detailed information, check out our hourly Koesan UV Index data.

Average daily maximum UV levels by month for Koesan. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)3469911111110743