Kosong weather in September

In September, Kosong sees average daytime highs of 23°C and overnight lows near 18°C, with 159 mm of rain across 10.7 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 24°C in the first days to 21°C by the end. The sky is clear or mostly clear about 34% of the time in September, and the air most often feels humid.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Kosong's 9th-clearest and 10th-windiest month. For the whole year in context, see Kosong's year-round climate.

Daytime high
23°
3rd warmest
Overnight low
18°
10th coldest
Rainfall
159 mm
10.7 wet days
Daylight
12 h 12 min
6:13 AM – 6:28 PM
Cloud cover
58%
9th clearest
Wind
10 km/h
10th windiest
Solar energy
4.14 kWh/m²
Travel score
6.6
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 24°C in the first days to 21°C by the end.

A typical September day in Kosong reaches about 23°C in the afternoon and slips back to 18°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 26°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12520
22420
32420
42420
52419
62419
72419
82419
92419
102319
112319
122318
132318
142318
152318
162318
172217
182217
192217
202217
212217
222217
232216
242116
252116
262116
272116
282115
292115
302115

How September really feels in Kosong

Once humidity and wind are folded in, September averages 0 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
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Kosong weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -4°486.559.60.0
Feb / -3°425.84.210.50.1
Mar / 537.63.211.71.9
Apr15° / 667.70.3134.7
May19° / 13°857.7014.16.6
Jun23° / 17°979.6014.66.7
Jul26° / 21°20613.7014.46.0
Aug26° / 22°21914.9013.55.8
Sep23° / 18°15910.7012.36.6
Oct18° / 12°807.10116.4
Nov12° / 748.20.79.93.2
Dec / -1°445.52.99.40.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 53%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14258
24258
34357
44357
54357
64456
74456
84456
94456
104456
114456
124555
134555
144654
154654
164753
174852
184852
194951
205050
215050
225149
235149
245248
255347
265347
275347
285347
295347
305347

Chance of precipitation in September

Any precipitation

Kosong gets around 159 mm of rain over 10.7 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 36% and peaks near 46% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
146
245
344
444
543
642
741
841
940
1040
1139
1239
1338
1438
1537
1636
1735
1834
1934
2033
2132
2231
2331
2430
2530
2629
2728
2828
2927
3027

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the humid band about 31% of days. Sticky, muggy-or-worse air turns up on roughly 23% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1110353717
2111373615
3112383514
4213393412
5214403311
631540329
731740328
841840317
952040306
1062239295
1172339274
1282538263
13102737242
14112836232
15133034211
16153233191
17173332181
18193430161
19213529140
20233628120
21253727110
2227372690
2330382580
2432382370
2535382260
2637382140
2739381940
2842371830
2944371720
3047361620

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 10 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over September. Sunrise moves from 6:00 AM to 6:26 AM, and sunset from 6:52 PM to 6:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.96:006:52
212.86:016:50
312.86:016:49
412.76:026:47
512.76:036:46
612.76:046:44
712.66:056:43
812.66:066:41
912.56:076:39
1012.56:086:38
1112.56:096:36
1212.46:106:34
1312.46:106:33
1412.36:116:31
1512.36:126:29
1612.26:136:28
1712.26:146:26
1812.26:156:24
1912.16:166:23
2012.16:176:21
2112.06:186:20
2212.06:196:18
2311.96:196:16
2411.96:206:15
2511.96:216:13
2611.86:226:11
2711.86:236:10
2811.76:246:08
2911.76:256:07
3011.66:266:05

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.14 kWh/m².

For context, solar energy here swings from a low near 2.32 kWh/m² to a high of 5.88 kWh/m² in May across the year — September's 4.14 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.3Bright
34.3Bright
44.3Bright
54.3Bright
64.2Bright
74.2Bright
84.2Bright
94.2Bright
104.2Bright
114.2Bright
124.2Bright
134.1Bright
144.1Bright
154.1Bright
164.1Bright
174.1Bright
184.1Bright
194.1Bright
204.1Bright
214.0Bright
224.0Bright
234.0Bright
244.0Bright
254.0Bright
264.0Moderate
274.0Moderate
284.0Moderate
293.9Moderate
303.9Moderate
Planning a trip in September

Hazard calendar for Kosong

In seasonPeak

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

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

Kosong's rainy season runs July–September, 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 September a good time to visit Kosong?

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

6.6
Sightseeing
2nd-best month of the year
4.8
Beach & pool
4th-best month of the year

September is a reasonable time to visit Kosong for sightseeing.

What to pack for Kosong in September

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

In September, Kosong sees daytime highs around 23°C and nights near 18°C. Worth packing: light clothes and rain gear. About 11 days see rain.

light clothesrain gear

Sea temperature near Kosong in September

The nearest coast averages about 22°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 14 km away) is warmest in August at about 24°C and coldest in February near 8°C.

It's comfortable for a long swim from Jul 1 to Oct 3 — about 3.1 months when the water holds above 20°C.

10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan9Bracing
Feb8Bracing
Mar8Bracing
Apr11Bracing
May14Bracing
Jun18Cool
Jul22Refreshing
Aug24Warm
Sep22Refreshing
Oct19Cool
Nov15Cool
Dec12Bracing

UV index in Kosong in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Kosong peaks around August 17 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateLowAug 17UV 9Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May6High
Jun7Very high
Jul7Very high
Aug9Very high
Sep8Very high
Oct5Moderate
Nov3Moderate
Dec2Low

Air quality in Kosong in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Kosong is worst in March — around 46 µg/m³ PM2.5 (poor), about 2.4× the cleanest month (September, 19 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModerateMar 2046 µg/m³Sep 1120 µg/m³
PM2.5 (µg/m³)Level
Jan35Poor
Feb38Poor
Mar46Poor
Apr43Poor
May36Poor
Jun29Moderate
Jul23Moderate
Aug21Moderate
Sep19Moderate
Oct26Moderate
Nov31Moderate
Dec30Moderate
Location & terrain

Where is Kosong?

Kosong sits at 38.4°N, 128.5°E, 17 m above sea level, in South Korea. The nearest listed city is Sokcho, 22 km away.

YangguJumunjinHwacheonGangneungHoeyangChuncheon

Topography around Kosong

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

Within 3 km, the terrain around Kosong has significant variations in elevation — a maximum elevation change of 294 m around an average of 40 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,313 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,646 m.

The land around Kosong is covered by trees (51%) and cropland (23%) within 3 km, trees (50%) and water (41%) within 16 km, and trees (58%) and water (33%) within 80 km.

3 km
294 m
16 km
1,313 m
80 km
1,646 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Sokcho 22 km · Yanggu 52 km · Jumunjin 63 km · Hwacheon 73 km · Gangneung 78 km · T’ongch’ŏn-ŭp 81 km · Hoeyang 84 km · Chuncheon 85 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 Kosong (38.3788°, 128.4676°, elevation 17 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).