Thun weather in September

In September, Thun sees average daytime highs of 16°C and overnight lows near 8°C, with 137 mm of precipitation across 13.7 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 18°C in the first days to 15°C by the end. The sky is clear or mostly clear about 30% 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 Thun's 3rd-clearest and 9th-windiest month. For the whole year in context, see Thun's year-round climate.

Daytime high
16°
4th warmest
Overnight low
9th coldest
Precipitation
137 mm
13.7 wet days
Daylight
12 h 18 min
6:14 AM – 6:34 PM
Cloud cover
58%
3rd clearest
Wind
5 km/h
9th windiest
Solar energy
3.79 kWh/m²
Travel score
4.8
out of 10
Air quality
Excellent
PM10 12.4 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 18°C in the first days to 15°C by the end.

A typical September day in Thun reaches about 16°C in the afternoon and slips back to 8°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 21°C. Set against its neighbours, September runs about 4°C cooler than August and about 4°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
1189
2189
3189
4189
5189
6189
7189
8179
9179
10178
11178
12178
13178
14178
15178
16168
17168
18168
19167
20167
21167
22167
23157
24157
25157
26157
27157
28157
29156
30156

How September really feels in Thun

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.

Thun weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -5°10712.911.48.80.0
Feb / -5°10011.710.4100.0
Mar / -1°10814.19.511.61.0
Apr11° / 12014.86.713.32.4
May15° / 18318.32.614.83.8
Jun19° / 10°182180.415.64.9
Jul21° / 11°19316.80.215.35.6
Aug20° / 11°180160.1145.6
Sep16° / 13713.7112.44.8
Oct12° / 11212.42.810.63.1
Nov / -1°11713.27.99.20.6
Dec / -4°12213.711.48.40.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% 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 53%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15347
25248
35248
45248
55248
65248
75248
85248
95149
105050
115050
124951
134951
144951
154753
164753
174753
184654
194654
204555
214456
224456
234456
244357
254357
264258
274159
284060
293961
303961

Chance of precipitation in September

Any precipitationSnow

Thun gets around 137 mm of rain and snow over 13.7 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 46% and peaks near 47% on the wettest days, and about 1 day brings snow.

0%20%40%60%151015202530
Rain chance (%)Snow chance (%)
1462
2462
3462
4462
5462
6462
7472
8472
9473
10473
11473
12473
13473
14473
15473
16474
17474
18474
19464
20464
21464
22454
23454
24454
25455
26455
27455
28455
29455
30455

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 95% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
18020
28218
38317
48515
58713
68812
79010
8919
9928
10937
11946
12955
13964
14973
15973
16982
17982
18991
19991
20991
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 5 km/h in September.

Across September, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

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 5:54 AM to 6:33 AM, and sunset from 7:04 PM to 6:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:547:04
213.15:557:02
313.15:577:00
413.05:586:58
513.05:596:56
612.96:016:54
712.86:026:52
812.86:036:50
912.76:056:48
1012.76:066:46
1112.66:076:44
1212.66:096:42
1312.56:106:40
1412.46:116:38
1512.46:136:36
1612.36:146:34
1712.36:156:32
1812.26:176:30
1912.26:186:27
2012.16:196:25
2112.06:216:23
2212.06:226:21
2311.96:236:19
2411.96:256:17
2511.86:266:15
2611.86:276:13
2711.76:296:11
2811.66:306:09
2911.66:326:07
3011.56:336:05

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.79 kWh/m².

For context, solar energy here swings from a low near 1.17 kWh/m² to a high of 5.73 kWh/m² in July across the year — September's 3.79 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.4Bright
24.3Bright
34.3Bright
44.3Bright
54.2Bright
64.2Bright
74.2Bright
84.1Bright
94.1Bright
104.0Bright
114.0Moderate
124.0Moderate
133.9Moderate
143.9Moderate
153.8Moderate
163.8Moderate
173.7Moderate
183.7Moderate
193.6Moderate
203.6Moderate
213.5Moderate
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 Thun?

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

4.8
Sightseeing
4th-best month of the year
0.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Thun for sightseeing.

What to pack for Thun in September

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

In September, Thun sees daytime highs around 16°C and nights near 8°C. Pack rain gear. Worth having: a warm layer. About 14 days see rain.

rain geara warm layer

UV index in Thun 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 Thun peaks around July 15 at about 9 (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 9Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar5Moderate
Apr6High
May7Very high
Jun8Very high
Jul9Very high
Aug7Very high
Sep5High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Thun?

Thun sits at 46.8°N, 7.6°E, 560 m above sea level, in Switzerland. The nearest listed city is Steffisburg, 3.0 km away.

InterlakenKönizBernLauterbrunnenBurgdorfGrindelwaldFribourg

Topography around Thun

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

Within 3 km, the terrain around Thun has significant variations in elevation — a maximum elevation change of 456 m around an average of 603 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,858 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,156 m.

The land around Thun is covered by trees (39%) and artificial surfaces (23%) within 3 km, trees (43%) and grassland (43%) within 16 km, and trees (39%) and grassland (36%) within 80 km.

3 km
456 m
16 km
1,858 m
80 km
4,156 m
treesgrasslandcroplandartificial surfacesbare terrainsnow and icewatermoss and lichen
September weather nearby: Steffisburg 3.0 km · Interlaken 20 km · Köniz 25 km · Bern 26 km · Lauterbrunnen 28 km · Burgdorf 34 km · Grindelwald 35 km · Fribourg 36 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 Thun (46.7512°, 7.6217°, elevation 560 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).