Geoje weather in September

In September, Geoje sees average daytime highs of 24°C and overnight lows near 22°C, with 173 mm of rain across 9 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 25°C in the first days to 22°C by the end. The sky is clear or mostly clear about 37% of the time in September, and the air most often feels muggy.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Geoje's 9th-clearest and 5th-windiest month. For the whole year in context, see Geoje's year-round climate.

Daytime high
24°
3rd warmest
Overnight low
22°
10th coldest
Rainfall
173 mm
9 wet days
Daylight
12 h 12 min
6:13 AM – 6:26 PM
Cloud cover
56%
9th clearest
Wind
24 km/h
5th windiest
Solar energy
4.36 kWh/m²
Travel score
7.0
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 25°C in the first days to 22°C by the end.

A typical September day in Geoje reaches about 24°C in the afternoon and slips back to 22°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 26°C. Set against its neighbours, September runs about 2°C cooler than August and about 4°C warmer than October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12624
22524
32524
42524
52524
62523
72523
82523
92523
102523
112523
122423
132423
142423
152422
162422
172422
182422
192422
202322
212322
222321
232321
242321
252321
262321
272321
282221
292220
302220

How September really feels in Geoje

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.

Geoje weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan / 425.29.91.5
Feb / 515.610.72.0
Mar11° / 978.311.73.1
Apr14° / 12°1278.512.84.5
May17° / 16°132813.85.9
Jun20° / 19°1809.614.36.2
Jul24° / 23°24011.814.16.4
Aug26° / 25°18711.613.36.5
Sep24° / 22°173912.27.0
Oct20° / 18°785.211.17.3
Nov15° / 12°59610.25.3
Dec10° / 394.89.72.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% 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 50%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14456
24555
34456
44456
54555
64654
74654
84753
94654
104753
114753
124852
134852
144951
154951
165050
175050
185248
195248
205248
215347
225347
235347
245446
255446
265545
275545
285545
295545
305644

Chance of precipitation in September

Any precipitation

Geoje gets around 173 mm of rain over 9 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 30% and peaks near 37% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
137
236
336
436
535
635
735
835
935
1034
1134
1234
1333
1432
1531
1631
1730
1829
1928
2027
2126
2226
2325
2425
2524
2624
2723
2823
2922
3022

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 33% of days. Sticky, muggy-or-worse air turns up on roughly 58% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1019363322
20110373220
30111383118
40112393116
50213403014
60214412913
71315422911
8131742289
9141842278
10151942267
11162141256
12172240245
13282439234
14292538223
153112636213
163122835203
174132934182
184153033172
195163131162
205173230141
216183329131
227203327121
238213426111
24922342491
251023342381
261225332281
271326342071
281527331960
291627331850
301828321750

Wind in September

Winds average 24 km/h in September.

Across September, daily wind ranges from about 23 km/h on the calmest days to 24 km/h at its breeziest. It stays fairly steady from day to day.

0102030151015202530
Wind speed (km/h)Feels
123breezy
223breezy
323breezy
423breezy
523breezy
623breezy
723breezy
823breezy
923breezy
1023breezy
1124breezy
1224breezy
1324breezy
1424breezy
1524breezy
1624breezy
1724breezy
1824breezy
1924breezy
2024breezy
2124breezy
2224breezy
2324breezy
2424breezy
2524breezy
2624breezy
2724breezy
2824breezy
2924breezy
3024breezy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over September. Sunrise moves from 6:02 AM to 6:24 AM, and sunset from 6:48 PM to 6:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.86:026:48
212.76:036:46
312.76:036:45
412.76:046:44
512.66:056:42
612.66:066:41
712.56:066:39
812.56:076:38
912.56:086:36
1012.46:096:35
1112.46:096:33
1212.46:106:32
1312.36:116:30
1412.36:126:29
1512.36:126:27
1612.26:136:26
1712.26:146:24
1812.16:156:23
1912.16:156:21
2012.16:166:20
2112.06:176:18
2212.06:186:17
2312.06:186:16
2411.96:196:14
2511.96:206:13
2611.86:216:11
2711.86:216:10
2811.86:226:08
2911.76:236:07
3011.76:246:05

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.36 kWh/m².

For context, solar energy here swings from a low near 2.64 kWh/m² to a high of 5.93 kWh/m² in May across the year — September's 4.36 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.6Bright
34.6Bright
44.6Bright
54.6Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.5Bright
114.4Bright
124.4Bright
134.4Bright
144.4Bright
154.4Bright
164.4Bright
174.3Bright
184.3Bright
194.3Bright
204.3Bright
214.3Bright
224.3Bright
234.3Bright
244.3Bright
254.2Bright
264.2Bright
274.2Bright
284.2Bright
294.2Bright
304.2Bright
Planning a trip in September

Hazard calendar for Geoje

In seasonPeak

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

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

Geoje's rainy season runs April–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 Geoje?

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

7.0
Sightseeing
2nd-best month of the year
5.8
Beach & pool
2nd-best month of the year

September is one of the better times to visit Geoje for general sightseeing.

What to pack for Geoje in September

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

In September, Geoje sees daytime highs around 24°C and nights near 22°C. Worth packing: light clothes, rain gear and a windbreaker. About 9 days see rain.

light clothesrain geara windbreaker

Sea temperature near Geoje in September

The nearest coast averages about 25°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 17 km away) is warmest in August at about 26°C and coldest in February near 14°C.

It's comfortable for a long swim from Jun 17 to Nov 5 — about 4.7 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb14Bracing
Mar14Bracing
Apr15Bracing
May17Cool
Jun20Refreshing
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec17Cool

UV index in Geoje in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Geoje peaks around August 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 20UV 9Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar6High
Apr7High
May8Very high
Jun8Very high
Jul8Very high
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Geoje 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 Geoje is worst in April — around 37 µg/m³ PM2.5 (poor), about 2.2× the cleanest month (September, 17 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateApr 1637 µg/m³Sep 2117 µg/m³
PM2.5 (µg/m³)Level
Jan23Moderate
Feb27Moderate
Mar35Poor
Apr37Poor
May35Poor
Jun27Moderate
Jul20Moderate
Aug19Moderate
Sep17Moderate
Oct17Moderate
Nov21Moderate
Dec19Moderate
Location & terrain

Where is Geoje?

Geoje sits at 34.8°N, 128.7°E, 11 m above sea level, in South Korea. The nearest listed city is Sinhyeon, 10 km away.

GoseongBusanChangwonKimhaeNaesŏ

Topography around Geoje

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

Within 3 km, the terrain around Geoje has significant variations in elevation — a maximum elevation change of 406 m around an average of 61 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 581 m; within 80 km, large variations in elevation — a maximum elevation change of 933 m.

The land around Geoje is covered by water (47%) and trees (43%) within 3 km, water (65%) and trees (28%) within 16 km, and water (62%) and trees (29%) within 80 km.

3 km
406 m
16 km
581 m
80 km
933 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Sinhyeon 10 km · Kyosai 11 km · Tongyeong 26 km · Goseong 39 km · Busan 44 km · Changwon 46 km · Kimhae 49 km · Naesŏ 51 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 Geoje (34.8138°, 128.7056°, elevation 11 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).