Ansan-si, South Korea climate

Cwa Monsoon-influenced humid subtropical

Ansan-si has a strongly seasonal cool-temperate climate (Monsoon-influenced humid subtropical, Köppen Cwa). The hottest month is August with an average daily high near 29°C, while the coldest is January averaging around −6°C at night. Precipitation totals about 1284 mm a year and is strongly seasonal — August alone averages 327 mm while January barely receives 12 mm.

☀️ Summers

Warm

Highs near 29°C in August.

About 6 days a year above 32 °C

❄️ Winters

Cold

Lows near −6°C in January.

About 66 freezing nights a year

🌧️ Rain

Wet

About 1284 mm of rain a year.

Wettest in August

⛅ Sky & trend

Partly cloudy

A roughly even mix of sun and cloud.

+0.6 °C vs 50 years ago

Temperature & precipitation

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

Clear vs cloudy days

Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day counts

Ansan-si climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	2	5	10	16	22	26	28	29	26	20	12	5
Avg temp (°C)	−2	1	6	12	17	22	25	26	22	16	8	1
Avg low (°C)	−6	−3	1	7	13	18	21	22	18	11	4	−3
Precipitation (mm)	12	23	41	63	113	114	323	327	132	62	51	22

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	2	5	10	16	22	26
Avg temp (°C)	−2	1	6	12	17	22
Avg low (°C)	−6	−3	1	7	13	18
Precipitation (mm)	12	23	41	63	113	114

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	28	29	26	20	12	5
Avg temp (°C)	25	26	22	16	8	1
Avg low (°C)	21	22	18	11	4	−3
Precipitation (mm)	323	327	132	62	51	22

How often — frequency of weather events

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	4	4	4	6	6	7	13	10	7	5	6	5
Days with high ≥ 32°C (days)	—	—	—	0.0	—	0.2	2	4	0.2	—	—	—
Days with low ≤ 0°C (days)	20	17	7	0.1	—	—	—	—	—	0.1	5	17

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Days with measurable rain (days)	4	4	4	6	6	7
Days with high ≥ 32°C (days)	—	—	—	0.0	—	0.2
Days with low ≤ 0°C (days)	20	17	7	0.1	—	—

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	13	10	7	5	6	5
Days with high ≥ 32°C (days)	2	4	0.2	—	—	—
Days with low ≤ 0°C (days)	—	—	—	0.1	5	17

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	51	50	52	55	58	67	75	65	56	46	52	51
Clear days (≤ 30% cloud)	8	8	9	8	8	4	2	5	8	12	8	8
Partly cloudy days (30–70%)	14	12	13	10	10	10	8	10	10	12	12	14
Cloudy days (≥ 70%)	9	8	10	12	13	16	20	16	12	8	10	9
Relative humidity (%)	76	74	74	74	75	78	85	84	79	75	76	77
Wind speed (m/s)	3.3	3.3	3.2	3.1	2.8	2.3	2.7	2.6	2.5	2.7	3.1	3.3

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	51	50	52	55	58	67
Clear days (≤ 30% cloud)	8	8	9	8	8	4
Partly cloudy days (30–70%)	14	12	13	10	10	10
Cloudy days (≥ 70%)	9	8	10	12	13	16
Relative humidity (%)	76	74	74	74	75	78
Wind speed (m/s)	3.3	3.3	3.2	3.1	2.8	2.3

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	75	65	56	46	52	51
Clear days (≤ 30% cloud)	2	5	8	12	8	8
Partly cloudy days (30–70%)	8	10	10	12	12	14
Cloudy days (≥ 70%)	20	16	12	8	10	9
Relative humidity (%)	85	84	79	75	76	77
Wind speed (m/s)	2.7	2.6	2.5	2.7	3.1	3.3

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 25 years of daily observations at Incheon, a weather station, about 23 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 →