Geneva weather in September

In September, Geneva sees average daytime highs of 19°C and overnight lows near 10°C, with 109 mm of rain across 12.2 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 20°C in the first days to 17°C by the end. The sky is clear or mostly clear about 32% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 12 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Geneva's 3rd-clearest and 9th-windiest month. For the whole year in context, see Geneva's year-round climate.

Daytime high
19°
4th warmest
Overnight low
10°
9th coldest
Rainfall
109 mm
12.2 wet days
Daylight
12 h 18 min
6:20 AM – 6:39 PM
Cloud cover
57%
3rd clearest
Wind
6 km/h
9th windiest
Solar energy
3.83 kWh/m²
Travel score
5.7
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 20°C in the first days to 17°C by the end.

A typical September day in Geneva reaches about 19°C in the afternoon and slips back to 10°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 24°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)
12112
22111
32011
42011
52011
62011
72011
82011
92011
101910
111910
121910
131910
141910
151910
161910
171910
181810
19189
20189
21189
22189
23189
24189
25179
26179
27179
28179
29178
30178

How September really feels in Geneva

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.

Geneva weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -2°11512.57.48.80.0
Feb / -2°9910.97100.4
Mar10° / 10912.74.811.62.2
Apr14° / 10913.52.813.33.6
May17° / 144160.414.74.8
Jun21° / 12°12314.8015.55.8
Jul23° / 13°12312.8015.26.6
Aug23° / 13°11712.70146.6
Sep19° / 10°10912.2012.35.7
Oct14° / 11212.40.510.73.9
Nov / 12513.54.29.21.4
Dec / -1°13113.47.28.50.1

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 18% of September, with mostly cloudy or overcast conditions the remaining 51%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15743
25644
35644
45644
55644
65644
75545
85644
95545
105545
115446
125347
135347
145248
155149
164951
174951
184852
194654
204555
214555
224357
234456
244357
254258
264159
274159
284159
294060
303961

Chance of precipitation in September

Any precipitation

Geneva gets around 109 mm of rain over 12.2 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 41% and peaks near 45% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
139
239
339
439
539
639
739
839
940
1040
1140
1240
1341
1441
1541
1642
1742
1842
1942
2042
2143
2243
2343
2443
2543
2644
2744
2844
2945
3045

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 79% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
160346
261336
363325
465314
566304
667303
768293
870282
971272
1073261
1173261
1274251
1375241
1477230
1578220
1679210
1781190
1882180
1984160
2085150
2187130
2288120
2389110
2490100
259190
269280
279370
289460
299460
309550

Wind in September

Winds average 6 km/h in September.

Across September, daily wind ranges from about 6 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 12 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over September. Sunrise moves from 6:01 AM to 6:39 AM, and sunset from 7:10 PM to 6:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.26:017:10
213.16:027:08
313.06:037:06
413.06:047:04
512.96:067:02
612.96:077:00
712.86:086:58
812.86:106:56
912.76:116:54
1012.76:126:52
1112.66:146:50
1212.56:156:48
1312.56:166:46
1412.46:176:44
1512.46:196:41
1612.36:206:39
1712.36:216:37
1812.26:236:35
1912.26:246:33
2012.16:256:31
2112.06:276:29
2212.06:286:27
2311.96:296:25
2411.96:316:23
2511.86:326:21
2611.86:336:19
2711.76:356:17
2811.66:366:15
2911.66:376:13
3011.56:396:11

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.83 kWh/m².

For context, solar energy here swings from a low near 1.13 kWh/m² to a high of 5.85 kWh/m² in July across the year — September's 3.83 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.4Bright
44.4Bright
54.3Bright
64.3Bright
74.2Bright
84.2Bright
94.1Bright
104.1Bright
114.0Bright
124.0Bright
134.0Moderate
143.9Moderate
153.9Moderate
163.8Moderate
173.8Moderate
183.7Moderate
193.6Moderate
203.6Moderate
213.6Moderate
223.5Moderate
233.5Moderate
243.4Moderate
253.4Moderate
263.3Moderate
273.3Moderate
283.2Moderate
293.2Moderate
303.1Moderate
Planning a trip in September

Is September a good time to visit Geneva?

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

5.7
Sightseeing
4th-best month of the year
2.3
Beach & pool
4th-best month of the year

September is a reasonable time to visit Geneva for sightseeing.

What to pack for Geneva in September

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

In September, Geneva sees daytime highs around 19°C and nights near 10°C. Worth packing: rain gear. About 12 days see rain.

rain gear

UV index in Geneva in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Geneva peaks around July 15 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 15UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5High
May7High
Jun7Very high
Jul9Very high
Aug7High
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Geneva 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 Geneva is worst in April — around 15 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1015 µg/m³Nov 1210 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb12Moderate
Mar15Moderate
Apr15Moderate
May13Moderate
Jun15Moderate
Jul11Good
Aug11Good
Sep11Good
Oct10Good
Nov10Good
Dec11Good
Location & terrain

Where is Geneva?

Geneva sits at 46.2°N, 6.1°E, 400 m above sea level, in Switzerland. The nearest listed city is Carouge, 2.0 km away.

NyonAnnecy-le-Vieux

Topography around Geneva

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

Within 3 km, the terrain around Geneva has only modest variations in elevation — a maximum elevation change of 93 m around an average of 403 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,154 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,604 m.

The land around Geneva is covered by artificial surfaces (46%) and trees (34%) within 3 km, trees (43%) and grassland (22%) within 16 km, and trees (54%) and grassland (29%) within 80 km.

3 km
93 m
16 km
1,154 m
80 km
4,604 m
treesgrasslandcroplandartificial surfacesbare terrainsnow and icewater
September weather nearby: Carouge 2.0 km · Lancy 3.0 km · Onex 4.0 km · Vernier 5.0 km · Meyrin 6.0 km · Annemasse 7.0 km · Nyon 21 km · Annecy-le-Vieux 31 km

Switzerland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / J
230 V · 50 Hz
Prices
≈ 112% of US
price level, 2025
GDP per capita
$114,769
2025
Happiness
7.0 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
0.6
per 100k, 2023
Road deaths
2.2
per 100k/yr, 2019
Income group
High
World Bank
English
High
EF EPI 564
Religion
Roman Catholic 34%none 29%Protestant 23%other Christian 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 Geneva (46.2022°, 6.1457°, elevation 400 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).