Cheonan, South Korea climate

Cwa Monsoon-influenced humid subtropical

Cheonan has a strongly seasonal cool-temperate climate (Monsoon-influenced humid subtropical, Köppen Cwa). The hottest month is August with an average daily high near 30°C, while the coldest is January averaging around −8°C at night. Precipitation totals about 788 mm a year and is strongly seasonal — July alone averages 228 mm while January barely receives 9 mm.

☀️ Summers

Warm

Highs near 30°C in August.

❄️ Winters

Very cold

Lows near −8°C in January.

🌧️ Rain

Moderate rainfall

About 788 mm of rain a year.

Wettest in July

⛅ Sky & trend

Partly cloudy

A roughly even mix of sun and cloud.

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Hours of sunshine per day

Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)

Cheonan climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	3	5	11	18	24	27	29	30	26	20	12	5
Avg temp (°C)	−2	0	6	12	18	23	26	26	21	14	7	0
Avg low (°C)	−8	−5	0	6	12	18	22	22	16	8	2	−5
Precipitation (mm)	9	13	19	35	53	66	228	211	85	37	30	—

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	3	5	11	18	24	27
Avg temp (°C)	−2	0	6	12	18	23
Avg low (°C)	−8	−5	0	6	12	18
Precipitation (mm)	9	13	19	35	53	66

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	29	30	26	20	12	5
Avg temp (°C)	26	26	21	14	7	0
Avg low (°C)	22	22	16	8	2	−5
Precipitation (mm)	228	211	85	37	30	—

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	53	54	55	56	59	69	76	70	63	51	54	53
Relative humidity (%)	76	73	75	75	77	79	86	85	81	76	75	76
Wind speed (m/s)	3.3	3.3	3.2	3.0	2.6	2.1	2.4	2.4	2.5	2.7	3.1	3.3

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	53	54	55	56	59	69
Relative humidity (%)	76	73	75	75	77	79
Wind speed (m/s)	3.3	3.3	3.2	3.0	2.6	2.1

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	76	70	63	51	54	53
Relative humidity (%)	86	85	81	76	75	76
Wind speed (m/s)	2.4	2.4	2.5	2.7	3.1	3.3

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 25 years of daily observations at A 511 / Desiderio Aaf-pyeongtaek / Camp Humphreys Rok, a weather station, about 21 km from the city centre. The underlying daily records come from NOAA's global station network.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →