Daejeon weather in September

In September, Daejeon sees average daytime highs of 26°C and overnight lows near 17°C, with 138 mm of rain across 8.4 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 27°C in the first days to 24°C by the end. The sky is clear or mostly clear about 32% 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 Daejeon's 9th-clearest and 10th-windiest month. For the whole year in context, see Daejeon's year-round climate.

Daytime high
26°
4th warmest
Overnight low
17°
9th coldest
Rainfall
138 mm
8.4 wet days
Daylight
12 h 12 min
6:18 AM – 6:32 PM
Cloud cover
59%
9th clearest
Wind
8 km/h
10th windiest
Solar energy
4.18 kWh/m²
Travel score
6.9
out of 10

Daejeon is human settlement in South Korea.

Air quality
Elevated
PM2.5 18 µg/m³ · 2020

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 27°C in the first days to 24°C by the end.

A typical September day in Daejeon reaches about 26°C in the afternoon and slips back to 17°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 29°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12820
22820
32819
42719
52719
62719
72719
82718
92718
102718
112618
122618
132617
142617
152617
162617
172617
182516
192516
202516
212516
222515
232515
242415
252415
262414
272414
282414
292314
302314

How September really feels in Daejeon

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.

Daejeon 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 / -5°244.82.89.80.0
Feb / -3°324.71.810.60.7
Mar12° / 537.41.311.73.4
Apr19° / 787.70.212.96.3
May24° / 13°867.8013.97.2
Jun27° / 18°1238.9014.46.4
Jul29° / 22°23015.7014.24.7
Aug30° / 22°19715013.44.6
Sep26° / 17°1388.4012.26.9
Oct20° / 10°565.1011.17.3
Nov13° / 416.20.310.13.9
Dec / -3°2551.69.60.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 32% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 54%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13961
23862
33961
44060
53961
63961
73961
84060
94060
104159
114258
124357
134357
144555
154654
164654
174753
184852
194951
205050
215050
225149
235149
245149
255248
265248
275248
285347
295347
305446

Chance of precipitation in September

Any precipitation

Daejeon gets around 138 mm of rain over 8.4 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 29% and peaks near 43% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
143
242
341
440
539
638
737
836
935
1034
1133
1232
1331
1430
1529
1628
1727
1825
1924
2023
2122
2222
2321
2420
2520
2620
2719
2819
2918
3018

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 28% of days. Sticky, muggy-or-worse air turns up on roughly 24% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
11133031241
22143130221
32153329201
43163428191
54173527170
64183626150
75193725140
86203725120
98213724110
10922372390
111123362280
121224352170
131425342060
141626331950
151927321850
162128301740
172329291630
182530271530
192731261420
203031251220
213232231120
223432221010
23373221910
24393220810
25413219710
26443118610
27463117600
28493016500
29512915500
30552714400

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 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
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 6:06 AM to 6:30 AM, and sunset from 6:55 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.86:066:55
212.86:076:53
312.76:076:52
412.76:086:50
512.76:096:49
612.66:106:47
712.66:116:46
812.56:116:44
912.56:126:42
1012.56:136:41
1112.46:146:39
1212.46:156:38
1312.36:166:36
1412.36:166:35
1512.36:176:33
1612.26:186:32
1712.26:196:30
1812.16:206:28
1912.16:206:27
2012.16:216:25
2112.06:226:24
2212.06:236:22
2312.06:246:21
2411.96:256:19
2511.96:256:18
2611.86:266:16
2711.86:276:15
2811.86:286:13
2911.76:296:12
3011.76:306:10

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.18 kWh/m².

For context, solar energy here swings from a low near 2.34 kWh/m² to a high of 5.88 kWh/m² in May across the year — September's 4.18 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.2Bright
44.2Bright
54.2Bright
64.2Bright
74.2Bright
84.2Bright
94.2Bright
104.2Bright
114.2Bright
124.2Bright
134.2Bright
144.2Bright
154.2Bright
164.2Bright
174.2Bright
184.2Bright
194.2Bright
204.2Bright
214.1Bright
224.1Bright
234.1Bright
244.1Bright
254.1Bright
264.1Bright
274.1Bright
284.1Bright
294.0Bright
304.0Bright
Planning a trip in September

Hazard calendar for Daejeon

In seasonPeak

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

Daejeon's rainy season runs June–September, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Daejeon?

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

6.9
Sightseeing
3rd-best month of the year
6.4
Beach & pool
2nd-best month of the year

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

What to pack for Daejeon in September

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

In September, Daejeon sees daytime highs around 26°C and nights near 17°C. Worth packing: light clothes and rain gear. About 8 days see rain.

light clothesrain gear

UV index in Daejeon 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 Daejeon peaks around August 14 at about 8 (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 highHighModerateAug 14UV 8Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar5Moderate
Apr6High
May7High
Jun7Very high
Jul8Very high
Aug8Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Daejeon 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 Daejeon is worst in March — around 23 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (July, 13 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Daejeon's WHO annual average of 18 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 1623 µg/m³Jul 2213 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb20Moderate
Mar23Moderate
Apr20Moderate
May17Moderate
Jun16Moderate
Jul13Moderate
Aug13Moderate
Sep17Moderate
Oct19Moderate
Nov20Moderate
Dec18Moderate
Location & terrain

Where is Daejeon?

Daejeon sits at 36.3°N, 127.4°E, 58 m above sea level, in South Korea. The nearest listed city is Okcheon, 17 km away.

YŏnmuYeongdong

Topography around Daejeon

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

Within 3 km, the terrain around Daejeon has only modest variations in elevation — a maximum elevation change of 155 m around an average of 58 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 808 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,594 m.

The land around Daejeon is covered by artificial surfaces (69%) within 3 km, trees (67%) within 16 km, and trees (67%) and cropland (22%) within 80 km.

3 km
155 m
16 km
808 m
80 km
1,594 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Okcheon 17 km · Gongju 26 km · Sejong 28 km · Kinzan 29 km · Nonsan 31 km · Cheongju-si 33 km · Yŏnmu 35 km · Yeongdong 40 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 Daejeon (36.3491°, 127.3849°, elevation 58 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. 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).