Busan weather in September

In September, Busan sees average daytime highs of 24°C and overnight lows near 22°C, with 159 mm of rain across 8.8 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 26°C in the first days to 23°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 Busan's 9th-clearest and 5th-windiest month. For the whole year in context, see Busan's year-round climate.

Daytime high
24°
3rd warmest
Overnight low
22°
10th coldest
Rainfall
159 mm
8.8 wet days
Daylight
12 h 12 min
6:12 AM – 6:25 PM
Cloud cover
57%
9th clearest
Wind
22 km/h
5th windiest
Solar energy
4.24 kWh/m²
Travel score
7.0
out of 10

Busan is metropolitan city of South Korea.

Air quality
Elevated
PM2.5 17 µg/m³ · 2020
Density
4,267/km²
people per km²

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 26°C in the first days to 23°C by the end.

A typical September day in Busan 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
22624
32624
42623
52523
62523
72523
82523
92523
102523
112523
122522
132522
142422
152422
162422
172422
182422
192422
202421
212421
222321
232321
242321
252321
262321
272320
282320
292320
302220

How September really feels in Busan

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.

Busan 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 / 374.79.91.4
Feb / 475.110.72.0
Mar12° / 897.911.73.2
Apr15° / 12°1218.112.94.7
May18° / 16°1307.613.86.1
Jun21° / 19°1679.314.36.4
Jul25° / 23°22811.814.16.4
Aug27° / 25°18111.113.36.5
Sep24° / 22°1598.812.27.0
Oct20° / 17°724.511.17.4
Nov15° / 11°525.410.25.3
Dec10° / 334.19.72.7

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
24456
34456
44555
54555
64555
74654
84654
94753
104852
114852
124852
134852
144951
155050
165149
175149
185149
195248
205347
215347
225446
235446
245545
255545
265545
275644
285644
295644
305644

Chance of precipitation in September

Any precipitation

Busan gets around 159 mm of rain over 8.8 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 29% and peaks near 36% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
136
236
335
435
535
634
734
834
934
1033
1133
1232
1332
1431
1530
1629
1729
1828
1927
2027
2126
2225
2325
2424
2524
2624
2723
2822
2922
3021

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 32% of days. Sticky, muggy-or-worse air turns up on roughly 56% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
10111363220
20112373119
30213383017
40214392915
50216392814
61317402812
71418402710
8141941269
9152141258
10162240247
11172340236
12282439225
13292638214
143102737204
153122836183
164132935173
174152934163
185163032142
196173131132
207183130122
217203229112
228213227101
231022332691
241123332481
251224322371
261425322261
271625312161
281727311950
291928311840
302128301740

Wind in September

Winds average 22 km/h in September.

Across September, daily wind ranges from about 21 km/h on the calmest days to 22 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
121breezy
221breezy
321breezy
421breezy
521breezy
621breezy
721breezy
821breezy
921breezy
1021breezy
1122breezy
1222breezy
1322breezy
1422breezy
1522breezy
1622breezy
1722breezy
1822breezy
1922breezy
2022breezy
2122breezy
2222breezy
2322breezy
2422breezy
2522breezy
2622breezy
2722breezy
2822breezy
2921breezy
3021breezy

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 6:00 AM to 6:23 AM, and sunset from 6:47 PM to 6:04 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.86:006:47
212.76:016:45
312.76:026:44
412.76:036:43
512.66:036:41
612.66:046:40
712.66:056:38
812.56:066:37
912.56:066:35
1012.46:076:34
1112.46:086:32
1212.46:096:31
1312.36:096:29
1412.36:106:28
1512.36:116:26
1612.26:126:25
1712.26:126:23
1812.16:136:22
1912.16:146:20
2012.16:156:19
2112.06:156:17
2212.06:166:16
2312.06:176:14
2411.96:186:13
2511.96:196:11
2611.86:196:10
2711.86:206:08
2811.86:216:07
2911.76:226:05
3011.76:236:04

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.24 kWh/m².

For context, solar energy here swings from a low near 2.64 kWh/m² to a high of 5.88 kWh/m² in May across the year — September's 4.24 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.4Bright
54.4Bright
64.4Bright
74.4Bright
84.3Bright
94.3Bright
104.3Bright
114.3Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.2Bright
174.2Bright
184.2Bright
194.2Bright
204.2Bright
214.2Bright
224.2Bright
234.2Bright
244.1Bright
254.1Bright
264.1Bright
274.1Bright
284.1Bright
294.1Bright
304.0Bright
Planning a trip in September

Hazard calendar for Busan

In seasonPeak

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

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

Busan'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 Busan?

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
6.0
Beach & pool
2nd-best month of the year

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

What to pack for Busan in September

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

In September, Busan 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 Busan 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 offshore 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 7 — about 4.7 months when the water holds above 20°C.

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

UV index in Busan 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 Busan peaks around August 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 18UV 9Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5High
Apr7High
May8Very high
Jun8Very high
Jul8Very high
Aug9Very high
Sep9Very high
Oct5High
Nov4Moderate
Dec2Moderate

Air quality in Busan 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 Busan is worst in March — around 21 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (August, 13 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Busan's WHO annual average of 17 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2121 µg/m³Aug 1913 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb18Moderate
Mar21Moderate
Apr21Moderate
May20Moderate
Jun17Moderate
Jul14Moderate
Aug13Moderate
Sep14Moderate
Oct16Moderate
Nov18Moderate
Dec15Moderate
Location & terrain

Where is Busan?

Busan sits at 35.1°N, 129.0°E, 15 m above sea level, in South Korea. The nearest listed city is Kimhae, 20 km away.

ChangwonUngsangGeojeSinhyeonKyosai

Topography around Busan

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

Within 3 km, the terrain around Busan has significant variations in elevation — a maximum elevation change of 485 m around an average of 75 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 636 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,204 m.

The land around Busan is covered by artificial surfaces (50%), trees (26%) and water (21%) within 3 km, water (51%) and artificial surfaces (24%) within 16 km, and water (53%) and trees (36%) within 80 km.

3 km
485 m
16 km
636 m
80 km
1,204 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Kimhae 20 km · Gijang 23 km · Yangsan 27 km · Changwon 35 km · Ungsang 36 km · Geoje 44 km · Sinhyeon 44 km · Kyosai 49 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 Busan (35.1017°, 129.03°, 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).