Osan weather in August

In August, Osan sees average daytime highs of 29°C and overnight lows near 22°C, with 231 mm of rain across 14 wet days and about 13.4 hours of daylight. It is the 1st-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 30°C in the first days to 28°C by the end. The sky is clear or mostly clear about 30% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 13 h 54 min at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is Osan's 11th-clearest and 10th-windiest month. For the whole year in context, see Osan's year-round climate.

Daytime high
29°
1st warmest
Overnight low
22°
12th coldest
Rainfall
231 mm
14 wet days
Daylight
13 h 24 min
5:53 AM – 7:19 PM
Cloud cover
63%
11th clearest
Wind
9 km/h
10th windiest
Solar energy
4.37 kWh/m²
Travel score
5.0
out of 10

Osan is city of Gyeonggi-do, South Korea.

Density
5,584/km²
people per km²

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

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 30°C in the first days to 28°C by the end.

A typical August day in Osan reaches about 29°C in the afternoon and slips back to 22°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 32°C. Set against its neighbours, August runs about 1°C warmer than July and about 4°C warmer than September.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13024
23024
33024
43024
53024
63024
73023
83023
93023
103023
113023
123023
133023
143023
152923
162923
172923
182922
192922
202922
212922
222922
232922
242822
252821
262821
272821
282821
292821
302820
312820

How August really feels in Osan

Once humidity and wind are folded in, August averages 18 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
18
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in August is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Osan weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -6°213.82.39.70.0
Feb / -4°274.11.710.60.3
Mar11° / 396.1111.72.9
Apr17° / 697.1012.95.9
May23° / 12°887.10147.3
Jun26° / 18°1187.6014.56.8
Jul28° / 22°27915.3014.35.1
Aug29° / 22°23114013.45.0
Sep26° / 17°1247.8012.37.0
Oct20° / 10°555.20117.2
Nov12° / 477.30.3103.5
Dec / -4°235.11.69.50.2

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 14% of August, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24456
34555
44654
54555
64555
74555
84456
94456
104456
114456
124456
134456
144456
154357
164357
174357
184357
194258
204258
214258
224258
234258
244258
254357
264357
274456
284555
294555
304555
314654

Chance of precipitation in August

Any precipitation

Osan gets around 231 mm of rain over 14 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 44% and peaks near 48% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
148
248
348
448
547
647
747
846
945
1045
1144
1244
1343
1443
1543
1643
1743
1843
1943
2043
2143
2243
2343
2443
2543
2643
2743
2842
2942
3041
3140

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the oppressive band about 46% of days. Sticky, muggy-or-worse air turns up on roughly 90% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1001135630
2002135530
3002135431
4002135431
5002135431
6002145331
7002155231
8002155231
9003165130
10003185029
11003195028
12003205126
13014215025
14014234923
15015244922
16015264820
17016274718
18016294617
19017304615
20028324514
21029334412
220210344311
23021136429
24131336408
25131436397
26131637376
27141737365
28151937345
29152137324
30162237303
31172437293

Wind in August

Winds average 9 km/h in August.

Across August, daily wind ranges from about 9 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 54 min at the start of August to 12 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 60 minutes over August. Sunrise moves from 5:40 AM to 6:06 AM, and sunset from 7:36 PM to 6:58 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:407:36
213.95:417:35
313.95:427:34
413.85:427:33
513.85:437:32
613.85:447:31
713.75:457:30
813.75:467:28
913.75:477:27
1013.65:487:26
1113.65:487:25
1213.65:497:24
1313.55:507:23
1413.55:517:21
1513.55:527:20
1613.45:537:19
1713.45:547:18
1813.45:547:16
1913.35:557:15
2013.35:567:14
2113.35:577:12
2213.25:587:11
2313.25:597:10
2413.16:007:08
2513.16:007:07
2613.16:017:05
2713.06:027:04
2813.06:037:02
2913.06:047:01
3012.96:056:59
3112.96:066:58

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.37 kWh/m².

For context, solar energy here swings from a low near 2.31 kWh/m² to a high of 5.85 kWh/m² in May across the year — August's 4.37 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.5Bright
114.5Bright
124.5Bright
134.4Bright
144.4Bright
154.4Bright
164.4Bright
174.4Bright
184.3Bright
194.3Bright
204.3Bright
214.3Bright
224.3Bright
234.3Bright
244.3Bright
254.3Bright
264.3Bright
274.3Bright
284.3Bright
294.3Bright
304.3Bright
314.3Bright
Planning a trip in August

Hazard calendar for Osan

In seasonPeak

In August, Osan sits inside its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.

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

Osan'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 August a good time to visit Osan?

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

5.0
Sightseeing
7th-best month of the year
6.3
Beach & pool
3rd-best month of the year

August is a reasonable time to visit Osan for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Osan in August

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

In August, Osan sees daytime highs around 29°C and nights near 22°C. Pack light clothes and rain gear. About 14 days see rain.

light clothesrain gear

Sea temperature near Osan in August

The nearest coast averages about 23°C in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 40 km away) is warmest in August at about 23°C and coldest in February near 4°C.

It's comfortable for a long swim from Jul 12 to Oct 14 — 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
Jun16Cool
Jul21Refreshing
Aug23Refreshing
Sep23Refreshing
Oct20Cool
Nov15Cool
Dec10Bracing

UV index in Osan in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Osan peaks around August 11 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 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 highHighModerateAug 11UV 8Dec 23UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May6High
Jun7High
Jul8Very high
Aug8Very high
Sep7Very high
Oct5Moderate
Nov3Moderate
Dec2Low

Air quality in Osan in August

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Osan 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 Osan?

Osan sits at 37.2°N, 127.1°E, 22 m above sea level, in South Korea. The nearest listed city is Suwon, 16 km away.

Topography around Osan

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

Within 3 km, the terrain around Osan has only modest variations in elevation — a maximum elevation change of 138 m around an average of 39 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 496 m; within 80 km, large variations in elevation — a maximum elevation change of 1,126 m.

The land around Osan is covered by artificial surfaces (48%) and trees (25%) within 3 km, trees (39%) and artificial surfaces (32%) within 16 km, and trees (49%) within 80 km.

3 km
138 m
16 km
496 m
80 km
1,126 m
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Suwon 16 km · Pyeongtaek 18 km · Hwaseong-si 23 km · Anseong 24 km · Uiwang 26 km · Gunpo 26 km · Seonghwan 27 km · Ansan 29 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 Osan (37.1522°, 127.0706°, elevation 22 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).