Kos weather in September

In September, Kos sees average daytime highs of 24°C and overnight lows near 23°C, with 16 mm of rain across 1.8 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 25°C in the first days to 23°C by the end. The sky is clear or mostly clear about 93% 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 Kos's 3rd-clearest and 7th-windiest month. For the whole year in context, see Kos's year-round climate.

Daytime high
24°
3rd warmest
Overnight low
23°
10th coldest
Rainfall
16 mm
1.8 wet days
Daylight
12 h 12 min
5:58 AM – 6:12 PM
Cloud cover
8%
3rd clearest
Wind
23 km/h
7th windiest
Solar energy
5.76 kWh/m²
Travel score
9.3
out of 10

Kos is city on the homonymous island in Aegean Sea, Greece.

Density
286/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 25°C in the first days to 23°C by the end.

A typical September day in Kos reaches about 24°C in the afternoon and slips back to 23°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 26°C. Set against its neighbours, September runs about 2°C cooler than August and about 3°C warmer than October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12624
22524
32524
42524
52524
62524
72523
82523
92523
102523
112523
122523
132423
142423
152423
162423
172423
182423
192422
202422
212422
222422
232422
242422
252322
262322
272322
282322
292322
302321

Kos weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan14° / 12°17312.39.84.1
Feb14° / 12°12611.510.64.0
Mar15° / 13°788.311.75.0
Apr17° / 15°395.812.96.3
May20° / 18°163.113.98.0
Jun24° / 22°20.414.59.5
Jul26° / 24°00.114.39.6
Aug26° / 24°0013.49.4
Sep24° / 23°161.812.39.3
Oct22° / 20°624.9118.0
Nov19° / 17°1208.9106.5
Dec16° / 14°19012.89.54.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 93% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 4% of September, with mostly cloudy or overcast conditions the remaining 3%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
11000
21000
31000
41000
51000
61000
7991
8991
9991
10991
11991
12982
13982
14982
15982
16982
17982
18973
19964
20964
21955
22955
23955
24955
25946
26937
27937
28937
29937
30919

Chance of precipitation in September

Any precipitation

Kos gets around 16 mm of rain over 1.8 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 6% and peaks near 11% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
11
22
32
42
52
63
73
83
93
104
114
124
134
145
155
166
176
186
197
207
218
228
239
249
259
2610
2710
2810
2910
3011

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 45% of days. Sticky, muggy-or-worse air turns up on roughly 63% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
114154536
214164534
314174532
415184630
525194628
625204726
725214725
826224724
926234722
1026234821
1126244820
1227244819
1327244819
1428254818
1528254817
1629254816
17210264715
18210264715
19211264714
20312264613
21313274513
22314274512
23314274411
24415284310
2541628439
2651629428
2751729418
2851730407
2961731397
3061732396

Wind in September

Winds average 23 km/h in September.

Across September, daily wind ranges from about 21 km/h on the calmest days to 24 km/h at its breeziest. It stays fairly steady from day to day.

0102030151015202530
Wind speed (km/h)Feels
124breezy
224breezy
324breezy
424breezy
524breezy
624breezy
724breezy
824breezy
923breezy
1023breezy
1123breezy
1223breezy
1323breezy
1423breezy
1523breezy
1623breezy
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 5:46 AM to 6:10 AM, and sunset from 6:35 PM to 5:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:466:35
212.85:476:34
312.75:476:32
412.75:486:31
512.75:496:29
612.65:506:28
712.65:516:26
812.65:526:25
912.55:526:23
1012.55:536:22
1112.45:546:20
1212.45:556:18
1312.45:566:17
1412.35:576:15
1512.35:576:14
1612.25:586:12
1712.25:596:11
1812.26:006:09
1912.16:016:07
2012.16:026:06
2112.06:026:04
2212.06:036:03
2311.96:046:01
2411.96:056:00
2511.96:065:58
2611.86:075:56
2711.86:085:55
2811.76:085:53
2911.76:095:52
3011.76:105:50

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.76 kWh/m².

For context, solar energy here swings from a low near 2.2 kWh/m² to a high of 7.91 kWh/m² in June across the year — September's 5.76 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.5Intense
26.4Intense
36.4Intense
46.3Intense
56.3Intense
66.3Intense
76.2Intense
86.2Intense
96.1Intense
106.0Intense
116.0Intense
126.0Bright
135.9Bright
145.8Bright
155.8Bright
165.7Bright
175.7Bright
185.6Bright
195.6Bright
205.5Bright
215.5Bright
225.4Bright
235.4Bright
245.3Bright
255.3Bright
265.2Bright
275.2Bright
285.1Bright
295.0Bright
305.0Bright
Planning a trip in September

Hazard calendar for Kos

In seasonPeak

None of Kos's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Kos's rainy season runs November–February, 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 Kos?

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

9.3
Sightseeing
4th-best month of the year
7.8
Beach & pool
3rd-best month of the year

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

What to pack for Kos in September

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

In September, Kos sees daytime highs around 24°C and nights near 23°C. Worth packing: light clothes, sun protection and a windbreaker.

light clothessun protectiona windbreaker

Sea temperature near Kos 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 offshore is warmest in August at about 25°C and coldest in March near 17°C.

It's comfortable for a long swim from May 23 to Nov 28 — about 6.2 months when the water holds above 20°C.

15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan17Cool
Feb17Cool
Mar17Cool
Apr17Cool
May19Cool
Jun22Refreshing
Jul24Refreshing
Aug25Warm
Sep24Warm
Oct23Refreshing
Nov21Refreshing
Dec19Cool

UV index in Kos 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 Kos peaks around June 22 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 10 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateVery highModerateJun 22UV 9Jan 10UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar4Moderate
Apr8Very high
May8Very high
Jun10Very high
Jul9Very high
Aug9Very high
Sep8Very high
Oct5Moderate
Nov3Moderate
Dec2Moderate
Location & terrain

Where is Kos?

Kos sits at 36.9°N, 27.3°E, 10 m above sea level, in Greece. The nearest listed city is Turgutreis, 14 km away.

DidimMilasMarmarisYatağanSökeRhodes

Topography around Kos

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

Within 3 km, the terrain around Kos has only modest variations in elevation — a maximum elevation change of 196 m around an average of 22 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 830 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,389 m.

The land around Kos is covered by water (37%) and grassland (23%) within 3 km, water (74%) within 16 km, and water (74%) within 80 km.

3 km
196 m
16 km
830 m
80 km
1,389 m
treesshrubsgrasslandcroplandartificial surfaceswater
September weather nearby: Turgutreis 14 km · Bodrum 20 km · Didim 55 km · Milas 64 km · Marmaris 88 km · Yatağan 91 km · Söke 96 km · Rhodes 98 km

Greece travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 60% of US
price level, 2025
GDP per capita
$26,948
2025
Happiness
5.7 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
0.8
per 100k, 2023
Road deaths
8.3
per 100k/yr, 2019
Income group
High
World Bank
English
High
EF EPI 592
Religion
other 3%Muslim 2%

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 Kos (36.8929°, 27.2877°, elevation 10 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).