Naesŏ weather in September

In September, Naesŏ sees average daytime highs of 27°C and overnight lows near 18°C, with 154 mm of rain across 9.4 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 28°C in the first days to 25°C by the end. The sky is clear or mostly clear about 30% of the time in September, and the air most often feels humid.

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 Naesŏ's 9th-clearest and 10th-windiest month. For the whole year in context, see Naesŏ's year-round climate.

Daytime high
27°
4th warmest
Overnight low
18°
9th coldest
Rainfall
154 mm
9.4 wet days
Daylight
12 h 12 min
6:14 AM – 6:27 PM
Cloud cover
61%
9th clearest
Wind
8 km/h
10th windiest
Solar energy
4.13 kWh/m²
Travel score
6.5
out of 10

Naesŏ is human settlement in South Korea.

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 28°C in the first days to 25°C by the end.

A typical September day in Naesŏ reaches about 27°C in the afternoon and slips back to 18°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 30°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°35°151015202530
Avg high (°C)Avg low (°C)
12921
22821
32821
42820
52820
62820
72820
82820
92819
102719
112719
122719
132719
142718
152718
162718
172618
182618
192617
202617
212617
222617
232616
242516
252516
262516
272515
282515
292515
302515

How September really feels in Naesŏ

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.

Naesŏ weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -3°253.60.79.91.2
Feb10° / -1°354.30.410.72.4
Mar14° / 706.90.411.74.6
Apr20° / 977.7012.96.6
May24° / 13°1057.8013.87.2
Jun27° / 18°1529.4014.36.3
Jul29° / 23°22514.2014.14.7
Aug30° / 23°20214.3013.34.4
Sep27° / 18°1549.4012.26.5
Oct22° / 11°634.5011.17.7
Nov15° / 434.8010.15.5
Dec / -1°253.20.29.72.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 56%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13961
23862
33961
44060
54060
64060
74060
84060
94159
104159
114258
124357
134357
144357
154357
164456
174555
184654
194654
204654
214654
224852
234852
244951
254951
264951
275050
285149
295149
305149

Chance of precipitation in September

Any precipitation

Naesŏ gets around 154 mm of rain over 9.4 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 31% and peaks near 41% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
141
240
340
439
539
638
738
837
937
1036
1135
1234
1333
1432
1531
1630
1729
1828
1927
2027
2126
2225
2325
2424
2524
2623
2723
2822
2922
3022

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 27% of days. Sticky, muggy-or-worse air turns up on roughly 38% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1162334316
2162534295
3172634274
4182834264
5292934243
6292933233
73103033213
83123132202
94133132192
105143131181
116153130161
127173129151
138193128141
149203126131
1510223025120
1612242923110
1713252922110
1815272821100
191628281990
201829271880
211930271670
222131261560
232232261460
242432251350
252633251150
262932241040
273132241040
28343123930
29363122830
30393021830

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
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
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

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 6:25 AM, and sunset from 6:49 PM to 6:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.86:026:49
212.76:036:48
312.76:046:46
412.76:056:45
512.66:056:43
612.66:066:42
712.66:076:40
812.56:086:39
912.56:086:37
1012.46:096:36
1112.46:106:34
1212.46:116:33
1312.36:116:31
1412.36:126:30
1512.36:136:28
1612.26:146:27
1712.26:146:25
1812.16:156:24
1912.16:166:22
2012.16:176:21
2112.06:186:19
2212.06:186:18
2312.06:196:16
2411.96:206:15
2511.96:216:13
2611.86:216:12
2711.86:226:10
2811.86:236:09
2911.76:246:07
3011.76:256:06

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.13 kWh/m².

For context, solar energy here swings from a low near 2.68 kWh/m² to a high of 5.84 kWh/m² in May across the year — September's 4.13 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.3Bright
34.3Bright
44.3Bright
54.2Bright
64.2Bright
74.2Bright
84.2Bright
94.2Bright
104.2Bright
114.2Bright
124.1Bright
134.1Bright
144.1Bright
154.1Bright
164.1Bright
174.1Bright
184.1Bright
194.1Bright
204.1Bright
214.1Bright
224.1Bright
234.1Bright
244.1Bright
254.1Bright
264.1Bright
274.0Bright
284.0Bright
294.0Bright
304.0Bright
Planning a trip in September

Hazard calendar for Naesŏ

In seasonPeak

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

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

Naesŏ's rainy season runs May–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 Naesŏ?

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

6.5
Sightseeing
4th-best month of the year
6.5
Beach & pool
1st-best month of the year

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

What to pack for Naesŏ in September

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

In September, Naesŏ sees daytime highs around 27°C and nights near 18°C. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

Sea temperature near Naesŏ 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 53 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 Naesŏ in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September 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 Naesŏ 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
Mar6High
Apr7High
May8Very high
Jun8Very high
Jul8Very high
Aug9Very high
Sep8Very high
Oct5High
Nov4Moderate
Dec2Moderate

Air quality in Naesŏ 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 Naesŏ is worst in March — around 51 µg/m³ PM2.5 (poor), about 1.8× the cleanest month (August, 29 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModeratePoorMar 2051 µg/m³Aug 1029 µg/m³
PM2.5 (µg/m³)Level
Jan38Poor
Feb43Poor
Mar51Poor
Apr49Poor
May43Poor
Jun38Poor
Jul29Moderate
Aug29Moderate
Sep33Moderate
Oct36Poor
Nov40Poor
Dec35Moderate
Location & terrain

Where is Naesŏ?

Naesŏ sits at 35.2°N, 128.5°E, 62 m above sea level, in South Korea. The nearest listed city is Changwon, 15 km away.

MiryangGoseongChinjuSinhyeonKyosai

Topography around Naesŏ

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

Within 3 km, the terrain around Naesŏ has significant variations in elevation — a maximum elevation change of 526 m around an average of 151 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 752 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,871 m.

The land around Naesŏ is covered by trees (75%) within 3 km, trees (66%) within 16 km, and trees (54%) and water (30%) within 80 km.

3 km
526 m
16 km
752 m
80 km
1,871 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Changwon 15 km · Changnyeong 33 km · Kimhae 33 km · Miryang 34 km · Goseong 35 km · Chinju 40 km · Sinhyeon 42 km · Kyosai 45 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 Naesŏ (35.2497°, 128.52°, elevation 62 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).