Nyon weather in September

In September, Nyon sees average daytime highs of 18°C and overnight lows near 12°C, with 118 mm of rain across 13.2 wet days and about 12.4 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 16°C by the end. The sky is clear or mostly clear about 27% 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 Nyon's 4th-clearest and 10th-windiest month. For the whole year in context, see Nyon's year-round climate.

Daytime high
18°
4th warmest
Overnight low
12°
9th coldest
Rainfall
118 mm
13.2 wet days
Daylight
12 h 18 min
6:20 AM – 6:39 PM
Cloud cover
61%
4th clearest
Wind
7 km/h
10th windiest
Solar energy
3.73 kWh/m²
Travel score
5.3
out of 10

Nyon is archaeological site in Nyon in the canton of Vaud, Suisse.

Air quality
Good
PM2.5 7.7 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 20°C in the first days to 16°C by the end.

A typical September day in Nyon reaches about 18°C in the afternoon and slips back to 12°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 23°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°151015202530
Avg high (°C)Avg low (°C)
12013
22013
32013
42013
52013
61913
71912
81912
91912
101912
111912
121912
131912
141812
151812
161812
171811
181811
191811
201811
211711
221711
231711
241711
251711
261711
271710
281610
291610
301610

How September really feels in Nyon

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.

Nyon 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 / -0°12213.48.48.80.0
Feb / 10312.18.3100.1
Mar / 11213.25.811.61.7
Apr13° / 10914.12.913.33.0
May16° / 13515.90.414.74.4
Jun20° / 13°12815.6015.55.5
Jul22° / 15°13715.6015.26.0
Aug22° / 15°13314.90146.1
Sep18° / 12°11813.2012.45.3
Oct14° / 12213.70.610.73.5
Nov / 130144.39.21.2
Dec / 14114.77.88.50.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% 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 59%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14951
24951
34852
44852
54852
64753
74654
84654
94654
104654
114555
124555
134357
144357
154357
164258
174258
184060
193961
203862
213862
223763
233664
243664
253664
263565
273565
283367
293268
303268

Chance of precipitation in September

Any precipitation

Nyon gets around 118 mm of rain over 13.2 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 45% and peaks near 48% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
144
244
344
444
544
644
744
844
944
1044
1144
1244
1345
1445
1545
1645
1745
1845
1945
2045
2145
2245
2346
2446
2546
2646
2747
2847
2948
3048

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 70% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
1553114
2563113
3583012
4603010
561309
662308
762308
863307
964306
1065305
1165305
1266304
1366304
1467303
1568293
1669292
1770282
1871272
1972262
2074251
2175241
2276231
2377221
2479201
2580191
2681181
2782171
2883161
2985150
3086140

Wind in September

Winds average 7 km/h in September.

Across September, daily wind ranges from about 7 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

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 6:00 AM to 6:38 AM, and sunset from 7:10 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.26:007:10
213.16:017:08
313.06:037:06
413.06:047:04
512.96:057:02
612.96:077:00
712.86:086:58
812.86:096:56
912.76:106:53
1012.76:126:51
1112.66:136:49
1212.56:146:47
1312.56:166:45
1412.46:176:43
1512.46:186:41
1612.36:206:39
1712.36:216:37
1812.26:226:35
1912.26:246:33
2012.16:256:31
2112.06:266:29
2212.06:286:27
2311.96:296:25
2411.96:306:23
2511.86:326:21
2611.86:336:19
2711.76:346:16
2811.66:366:14
2911.66:376:12
3011.56:386:10

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.73 kWh/m².

For context, solar energy here swings from a low near 1.08 kWh/m² to a high of 5.84 kWh/m² in July across the year — September's 3.73 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.4Bright
24.4Bright
34.3Bright
44.3Bright
54.3Bright
64.2Bright
74.2Bright
84.1Bright
94.1Bright
104.0Bright
114.0Moderate
123.9Moderate
133.9Moderate
143.8Moderate
153.8Moderate
163.7Moderate
173.7Moderate
183.6Moderate
193.5Moderate
203.5Moderate
213.5Moderate
223.4Moderate
233.4Moderate
243.3Moderate
253.3Moderate
263.2Moderate
273.1Moderate
283.1Moderate
293.1Moderate
303.0Moderate
Planning a trip in September

Is September a good time to visit Nyon?

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

5.3
Sightseeing
4th-best month of the year
1.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Nyon for sightseeing.

What to pack for Nyon in September

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

In September, Nyon sees daytime highs around 18°C and nights near 12°C. Pack rain gear. About 13 days see rain.

rain gear

UV index in Nyon 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 Nyon peaks around July 15 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 9Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5High
May7High
Jun7Very high
Jul9Very high
Aug7High
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Nyon?

Nyon sits at 46.4°N, 6.2°E, 401 m above sea level, in Switzerland. The nearest listed city is Thonon-les-Bains, 18 km away.

MeyrinAnnemasseGenevaVernierLancyCarougeMorges

Topography around Nyon

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

Within 3 km, the terrain around Nyon has only modest variations in elevation — a maximum elevation change of 115 m around an average of 402 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,301 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,546 m.

The land around Nyon is covered by water (39%) and cropland (20%) within 3 km, trees (41%) and water (24%) within 16 km, and trees (53%) and grassland (31%) within 80 km.

3 km
115 m
16 km
1,301 m
80 km
4,546 m
treesgrasslandcroplandartificial surfacesbare terrainsnow and icewater
September weather nearby: Thonon-les-Bains 18 km · Meyrin 21 km · Annemasse 21 km · Geneva 21 km · Vernier 22 km · Lancy 24 km · Carouge 24 km · Morges 24 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 Nyon (46.3832°, 6.2396°, elevation 401 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).