Ansan weather in December

In December, Ansan sees average daytime highs of 5°C and overnight lows near -0°C, with 28 mm of precipitation across 5.8 wet days and about 9.5 hours of daylight. It is the 10th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 7°C in the first days to 3°C by the end. The sky is clear or mostly clear about 37% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 36 min at the start of December to 9 h 30 min by month's end. Set against the rest of the year, December is Ansan's 7th-clearest and 1st-windiest month. For the whole year in context, see Ansan's year-round climate.

Daytime high
10th warmest
Overnight low
-0°
3rd coldest
Precipitation
28 mm
5.8 wet days
Daylight
9 h 24 min
7:46 AM – 5:12 PM
Cloud cover
52%
7th clearest
Wind
16 km/h
1st windiest
Solar energy
2.24 kWh/m²
Travel score
0.2
out of 10

Ansan is city in South Korea.

Density
4,172/km²
people per km²
Founded
1986

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 7°C in the first days to 3°C by the end.

A typical December day in Ansan reaches about 5°C in the afternoon and slips back to -0°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between -0°C and 9°C. Set against its neighbours, December runs about 6°C cooler than November and about 3°C warmer than January.

-10°-5°10°15°151015202531
Avg high (°C)Avg low (°C)
172
272
372
472
561
661
761
861
961
1050
1150
1250
1350
1450
1550
1650
1740
184-1
194-1
204-1
214-1
224-1
234-1
244-1
254-1
263-1
273-2
283-2
293-2
303-2
313-2

How December really feels in Ansan

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 31 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
31
wind chill below the day's low

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Ansan weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -3°234.12.59.70.0
Feb / -1°304.31.310.60.0
Mar / 426.10.911.71.1
Apr12° / 797.3012.93.6
May17° / 13°1047.70145.9
Jun22° / 18°1277.6014.56.8
Jul25° / 22°29814.4014.36.0
Aug27° / 23°23912.8013.46.2
Sep24° / 19°1277.3012.37.3
Oct18° / 13°625.60116.7
Nov11° / 578.20.3103.1
Dec / -0°285.81.89.50.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 20% of December, with mostly cloudy or overcast conditions the remaining 43%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35644
45644
55644
65644
75644
85644
95644
105743
115743
125743
135743
145743
155842
165842
175842
185842
195941
205842
215842
225842
235941
245941
255842
265842
275743
285743
295644
305644
315545

Chance of precipitation in December

Any precipitationSnow

Ansan gets around 28 mm of rain and snow over 5.8 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 19% and peaks near 25% on the wettest days, and about 2 days bring snow. The odds ease toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1254
2254
3254
4244
5244
6234
7225
8225
9215
10215
11205
12205
13195
14195
15185
16185
17175
18176
19176
20176
21176
22177
23167
24167
25167
26168
27168
28168
29168
30168
31168

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 16 km/h in December, the windiest month of the year.

Across December, daily wind ranges from about 16 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1716light breeze
1816light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze
3116light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 36 min at the start of December to 9 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 7:34 AM to 7:52 AM, and sunset from 5:11 PM to 5:20 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.67:345:11
29.67:355:11
39.67:365:11
49.67:375:11
59.67:375:11
69.57:385:11
79.57:395:11
89.57:405:11
99.57:415:11
109.57:415:11
119.57:425:11
129.57:435:11
139.57:445:11
149.57:445:12
159.47:455:12
169.47:465:12
179.47:465:12
189.47:475:13
199.47:475:13
209.47:485:14
219.47:485:14
229.47:495:14
239.47:495:15
249.47:505:15
259.47:505:16
269.47:515:17
279.47:515:17
289.47:515:18
299.47:525:18
309.57:525:19
319.57:525:20

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.24 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.24 kWh/m² to a high of 5.83 kWh/m² in May across the year — December's 2.24 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.3Moderate
22.3Moderate
32.3Moderate
42.3Moderate
52.2Moderate
62.2Moderate
72.2Moderate
82.2Moderate
92.2Moderate
102.2Moderate
112.2Moderate
122.2Moderate
132.2Moderate
142.2Moderate
152.2Moderate
162.2Moderate
172.2Moderate
182.2Moderate
192.2Moderate
202.3Moderate
212.3Moderate
222.3Moderate
232.3Moderate
242.3Moderate
252.3Moderate
262.3Moderate
272.3Moderate
282.3Moderate
292.3Moderate
302.3Moderate
312.3Moderate
Planning a trip in December

Hazard calendar for Ansan

In seasonPeak

In December, Ansan sits inside its pacific typhoon season. The full year is below, with each hazard's peak months called out.

Ansan sits in the Pacific typhoon belt; the season peaks July–October.

Ansan's rainy season runs July–August, when most of the year's rain falls.

Pacific typhoon
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Ansan?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.2
Sightseeing
10th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Ansan.

What to pack for Ansan in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Ansan sees daytime highs around 5°C and nights near -0°C. Pack a warm layer. Worth having: a heavy coat. About 6 days see rain.

a warm layera heavy coat

Sea temperature near Ansan in December

The nearest coast averages about 10°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 18 km away) is warmest in August at about 24°C and coldest in February near 4°C.

It's comfortable for a long swim from Jul 11 to Oct 13 — about 3.1 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan6Bracing
Feb4Bracing
Mar5Bracing
Apr8Bracing
May12Bracing
Jun17Cool
Jul21Refreshing
Aug24Refreshing
Sep23Refreshing
Oct20Cool
Nov15Bracing
Dec10Bracing

UV index in Ansan in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ansan peaks around July 23 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJul 23UV 8Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May6High
Jun7High
Jul8Very high
Aug8Very high
Sep7High
Oct5Moderate
Nov3Moderate
Dec2Low

Air quality in Ansan in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Ansan is worst in March — around 160 µg/m³ PM2.5 (very unhealthy), about 2.0× the cleanest month (August, 81 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0306090120150180JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyVery unhealthyUnhealthyMar 13158 µg/m³Aug 1282 µg/m³
PM2.5 (µg/m³)Level
Jan145Unhealthy
Feb149Unhealthy
Mar160Very unhealthy
Apr127Unhealthy
May111Unhealthy
Jun98Unhealthy
Jul88Unhealthy
Aug81Unhealthy
Sep110Unhealthy
Oct132Unhealthy
Nov142Unhealthy
Dec133Unhealthy
Location & terrain

Where is Ansan?

Ansan sits at 37.3°N, 126.8°E, 15 m above sea level, in South Korea. The nearest listed city is Anyang-si, 12 km away.

Topography around Ansan

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ansan.

Within 3 km, the terrain around Ansan has only modest variations in elevation — a maximum elevation change of 198 m around an average of 24 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 470 m; within 80 km, large variations in elevation — a maximum elevation change of 1,126 m.

The land around Ansan is covered by artificial surfaces (58%) and trees (33%) within 3 km, trees (36%) and artificial surfaces (32%) within 16 km, and trees (39%) and water (27%) within 80 km.

3 km
198 m
16 km
470 m
80 km
1,126 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
December weather nearby: Anyang-si 12 km · Uiwang 12 km · Gunpo 12 km · Hwaseong-si 13 km · Siheungdong 16 km · Suwon 17 km · Gwangmyeong 18 km · Incheon 18 km

South Korea travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
220 V · 60 Hz
Prices
≈ 57% of US
price level, 2025
GDP per capita
$36,227
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
99%
of population, 2024
Homicide rate
0.5
per 100k, 2023
Road deaths
8.6
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 522
Religion
none 60%Protestant 17%Buddhist 16%Catholic 6%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Ansan (37.3236°, 126.8219°, elevation 15 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).