Yeonil weather in September

In September, Yeonil sees average daytime highs of 25°C and overnight lows near 19°C, with 154 mm of rain across 9.8 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 23°C by the end. The sky is clear or mostly clear about 26% 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 Yeonil's 9th-clearest and 8th-windiest month. For the whole year in context, see Yeonil's year-round climate.

Daytime high
25°
4th warmest
Overnight low
19°
10th coldest
Rainfall
154 mm
9.8 wet days
Daylight
12 h 12 min
6:10 AM – 6:24 PM
Cloud cover
63%
9th clearest
Wind
10 km/h
8th windiest
Solar energy
3.97 kWh/m²
Travel score
6.7
out of 10

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 23°C by the end.

A typical September day in Yeonil reaches about 25°C in the afternoon and slips back to 19°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 28°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)
12721
22721
32721
42721
52721
62620
72620
82620
92620
102620
112620
122519
132519
142519
152519
162519
172518
182518
192418
202418
212418
222417
232417
242417
252317
262317
272316
282316
292316
302316

How September really feels in Yeonil

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.

Yeonil 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 / -2°274.41.29.80.2
Feb / -1°334.51.210.61.2
Mar12° / 6170.911.73.4
Apr18° / 747.2012.96.0
May22° / 13°847.6013.97.1
Jun25° / 18°1208.5014.46.7
Jul28° / 23°19513014.25.2
Aug29° / 23°20213.5013.45.0
Sep25° / 19°1549.8012.26.7
Oct20° / 12°625011.17.2
Nov14° / 395010.14.8
Dec / -0°243.70.59.61.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 57%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13763
23763
33763
43763
53763
63664
73763
83862
93862
103961
114060
124060
134159
144258
154258
164456
174456
184654
194654
204654
214852
224852
234951
244951
254951
264951
274951
284951
295050
305149

Chance of precipitation in September

Any precipitation

Yeonil gets around 154 mm of rain over 9.8 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 33% 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
241
341
440
540
640
739
839
938
1038
1137
1236
1335
1435
1534
1633
1732
1831
1930
2029
2128
2227
2327
2426
2526
2625
2724
2824
2923
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 31% of days. Sticky, muggy-or-worse air turns up on roughly 37% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1052539293
2052639272
3062839252
4162939232
5173039212
6183138201
7193238181
82103338171
92113437151
103133436140
113143435130
124163534120
135173532110
146193531100
15721342990
16822342780
171024342570
181126332370
191227332160
201429332050
211530321850
221731321640
231932321440
242133311230
252333301130
262534291030
27273428820
28303327820
29333325720
30353324620

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 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 5:58 AM to 6:22 AM, and sunset from 6:46 PM to 6:02 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:586:46
212.85:596:45
312.76:006:44
412.76:016:42
512.66:026:41
612.66:026:39
712.66:036:38
812.56:046:36
912.56:056:35
1012.56:066:33
1112.46:066:31
1212.46:076:30
1312.36:086:28
1412.36:096:27
1512.36:106:25
1612.26:106:24
1712.26:116:22
1812.16:126:21
1912.16:136:19
2012.16:146:18
2112.06:146:16
2212.06:156:15
2312.06:166:13
2411.96:176:11
2511.96:186:10
2611.86:186:08
2711.86:196:07
2811.86:206:05
2911.76:216:04
3011.76:226:02

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.97 kWh/m².

For context, solar energy here swings from a low near 2.6 kWh/m² to a high of 5.84 kWh/m² in May across the year — September's 3.97 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.1Bright
44.1Bright
54.1Bright
64.1Bright
74.1Bright
84.0Bright
94.0Bright
104.0Bright
114.0Moderate
124.0Moderate
134.0Moderate
144.0Moderate
154.0Moderate
163.9Moderate
173.9Moderate
183.9Moderate
193.9Moderate
203.9Moderate
213.9Moderate
223.9Moderate
233.9Moderate
243.9Moderate
253.9Moderate
263.9Moderate
273.9Moderate
283.9Moderate
293.9Moderate
303.9Moderate
Planning a trip in September

Hazard calendar for Yeonil

In seasonPeak

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

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

Yeonil's rainy season runs June–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 Yeonil?

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

6.7
Sightseeing
3rd-best month of the year
5.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Yeonil for sightseeing.

What to pack for Yeonil in September

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

In September, Yeonil sees daytime highs around 25°C and nights near 19°C. Worth packing: light clothes and rain gear. About 10 days see rain.

light clothesrain gear

Sea temperature near Yeonil in September

The nearest coast averages about 24°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 31 km away) is warmest in August at about 25°C and coldest in February near 12°C.

It's comfortable for a long swim from Jun 25 to Oct 28 — about 4.1 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb12Bracing
Mar13Bracing
Apr14Bracing
May16Cool
Jun19Cool
Jul22Refreshing
Aug25Warm
Sep24Refreshing
Oct21Refreshing
Nov18Cool
Dec16Cool

UV index in Yeonil 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 Yeonil peaks around August 16 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 highVery highModerateAug 16UV 9Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun6High
Jul8Very high
Aug10Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Moderate

Air quality in Yeonil 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 Yeonil is worst in March — around 66 µg/m³ PM2.5 (unhealthy), about 1.9× the cleanest month (August, 34 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecPoorUnhealthyPoorPoorMar 1865 µg/m³Aug 1535 µg/m³
PM2.5 (µg/m³)Level
Jan51Poor
Feb57Unhealthy
Mar66Unhealthy
Apr60Unhealthy
May55Poor
Jun47Poor
Jul37Poor
Aug34Moderate
Sep39Poor
Oct47Poor
Nov56Unhealthy
Dec47Poor
Location & terrain

Where is Yeonil?

Yeonil sits at 36.0°N, 129.3°E, 4 m above sea level, in South Korea. The nearest listed city is Pohang, 5.0 km away.

EisenHayangUlsanCheongsong gunGyeongsan-si

Topography around Yeonil

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

Within 3 km, the terrain around Yeonil has significant variations in elevation — a maximum elevation change of 253 m around an average of 47 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 644 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,200 m.

The land around Yeonil is covered by trees (49%) and artificial surfaces (27%) within 3 km, trees (56%) within 16 km, and trees (56%) and water (30%) within 80 km.

3 km
253 m
16 km
644 m
80 km
1,200 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Pohang 5.0 km · Heunghae 12 km · Gyeongju 20 km · Eisen 35 km · Hayang 46 km · Ulsan 52 km · Cheongsong gun 53 km · Gyeongsan-si 56 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 Yeonil (36.0045°, 129.3185°, elevation 4 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).