Körfez weather in September

In September, Körfez sees average daytime highs of 25°C and overnight lows near 15°C, with 57 mm of rain across 7.9 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 10th-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 57% of the time in September, and the air most often feels comfortable.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Körfez's 4th-clearest and 4th-windiest month. For the whole year in context, see Körfez's year-round climate.

Daytime high
25°
4th warmest
Overnight low
15°
9th coldest
Rainfall
57 mm
7.9 wet days
Daylight
12 h 18 min
5:47 AM – 6:03 PM
Cloud cover
38%
4th clearest
Wind
8 km/h
4th windiest
Solar energy
4.48 kWh/m²
Travel score
7.6
out of 10

Körfez is district and town of the Kocaeli Province in Turkey.

Density
301/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 Körfez reaches about 25°C in the afternoon and slips back to 15°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 20°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)
12717
22717
32617
42617
52617
62617
72616
82616
92616
102616
112516
122516
132516
142516
152516
162515
172515
182515
192415
202415
212415
222415
232415
242414
252414
262314
272314
282314
292314
302314

How September really feels in Körfez

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.

Körfez weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 9513.66.29.41.1
Feb / 8112.65.310.41.7
Mar12° / 8812.92.711.73.0
Apr17° / 6610.80.513.15.2
May21° / 12°599.3014.26.9
Jun26° / 16°639.7014.97.2
Jul28° / 18°385.8014.67.3
Aug28° / 19°365.5013.67.1
Sep25° / 15°577.9012.37.6
Oct20° / 12°8110.4010.96.3
Nov14° / 7510.219.74.3
Dec / 103133.89.11.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 57% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 25%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18416
28416
38317
48317
58317
68218
78218
88218
98119
108119
118119
128020
137921
147921
157723
167624
177525
187426
197327
207129
217129
226931
236931
246832
256733
266634
276634
286535
296535
306436

Chance of precipitation in September

Any precipitation

Körfez gets around 57 mm of rain over 7.9 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 26% and peaks near 31% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
123
223
323
423
523
623
723
822
922
1022
1122
1222
1322
1423
1523
1624
1725
1825
1926
2027
2128
2229
2329
2430
2531
2631
2731
2831
2931
3030

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the comfortable band about 36% of days. Sticky, muggy-or-worse air turns up on roughly 8% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
192740221
2102940211
3113040191
4123139170
5143239150
6143338140
7153438120
8163538110
9173538100
1017363890
1118363880
1219363870
1319373770
1420373760
1520373660
1621383660
1722383550
1823383450
1924393350
2025393250
2126393140
2227392940
2329392840
2430402730
2532402530
2633402430
2734402320
2836402220
2937402120
3038402020

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
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 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over September. Sunrise moves from 5:32 AM to 6:02 AM, and sunset from 6:29 PM to 5:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:326:29
212.95:336:27
312.95:346:26
412.85:356:24
512.85:366:22
612.75:376:21
712.75:386:19
812.65:396:17
912.65:406:15
1012.55:416:14
1112.55:426:12
1212.55:436:10
1312.45:446:08
1412.45:456:07
1512.35:466:05
1612.35:476:03
1712.25:486:01
1812.25:496:00
1912.15:505:58
2012.15:515:56
2112.05:525:54
2212.05:535:53
2311.95:545:51
2411.95:555:49
2511.85:565:47
2611.85:575:46
2711.85:585:44
2811.76:005:42
2911.76:015:40
3011.66:025:39

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.48 kWh/m².

For context, solar energy here swings from a low near 1.5 kWh/m² to a high of 6.72 kWh/m² in July across the year — September's 4.48 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.1Bright
45.1Bright
55.0Bright
65.0Bright
74.9Bright
84.9Bright
94.8Bright
104.8Bright
114.7Bright
124.7Bright
134.6Bright
144.6Bright
154.5Bright
164.5Bright
174.4Bright
184.4Bright
194.3Bright
204.3Bright
214.2Bright
224.2Bright
234.1Bright
244.0Bright
254.0Moderate
263.9Moderate
273.9Moderate
283.8Moderate
293.8Moderate
303.7Moderate
Planning a trip in September

Is September a good time to visit Körfez?

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

7.6
Sightseeing
1st-best month of the year
6.7
Beach & pool
4th-best month of the year

September is one of the better times to visit Körfez for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Körfez in September

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

In September, Körfez sees daytime highs around 25°C and nights near 15°C. Worth packing: light clothes. About 8 days see rain.

light clothes

Sea temperature near Körfez in September

The nearest coast averages about 23°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 41 km away) is warmest in August at about 25°C and coldest in February near 7°C.

It's comfortable for a long swim from Jun 11 to Oct 10 — about 4 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan9Bracing
Feb7Bracing
Mar8Bracing
Apr10Bracing
May16Cool
Jun21Refreshing
Jul24Warm
Aug25Warm
Sep23Refreshing
Oct19Cool
Nov15Cool
Dec11Bracing

UV index in Körfez in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Körfez peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highModerateLowJun 23UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar4Moderate
Apr7High
May7High
Jun9Very high
Jul9Very high
Aug9Very high
Sep7High
Oct4Moderate
Nov2Moderate
Dec2Low

Air quality in Körfez 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 Körfez is worst in March — around 16 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (December, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMar 2316 µg/m³Dec 198 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar16Moderate
Apr16Moderate
May15Moderate
Jun13Moderate
Jul10Good
Aug10Good
Sep10Good
Oct10Good
Nov10Good
Dec8Good
Location & terrain

Where is Körfez?

Körfez sits at 40.8°N, 29.8°E, 57 m above sea level, in Turkey. The nearest listed city is Derince, 3.0 km away.

Topography around Körfez

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

Within 3 km, the terrain around Körfez has significant variations in elevation — a maximum elevation change of 400 m around an average of 87 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 951 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,600 m.

The land around Körfez is covered by artificial surfaces (52%) and trees (29%) within 3 km, trees (53%) within 16 km, and trees (48%) and water (27%) within 80 km.

3 km
400 m
16 km
951 m
80 km
1,600 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Derince 3.0 km · Gölcük 7.0 km · İzmit 12 km · Karamürsel 16 km · Gebze 30 km · İznik 38 km · Sapanca 42 km · Yalova 44 km

Turkey travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 41% of US
price level, 2025
GDP per capita
$18,599
2025
Happiness
5.3 / 10
World Happiness, 2025
Homicide rate
3.2
per 100k, 2023
Road deaths
6.7
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 488
Religion
Muslim 100%other 0%

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 Körfez (40.767°, 29.7828°, elevation 57 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. 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).