Locarno weather in September

In September, Locarno sees average daytime highs of 16°C and overnight lows near 8°C, with 178 mm of precipitation across 12.9 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 18°C in the first days to 14°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 Locarno's 7th-clearest and 9th-windiest month. For the whole year in context, see Locarno's year-round climate.

Daytime high
16°
4th warmest
Overnight low
9th coldest
Precipitation
178 mm
12.9 wet days
Daylight
12 h 18 min
6:09 AM – 6:29 PM
Cloud cover
58%
7th clearest
Wind
4 km/h
9th windiest
Solar energy
3.73 kWh/m²
Travel score
4.6
out of 10
Air quality
Moderate
PM2.5 10.5 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 14°C by the end.

A typical September day in Locarno reaches about 16°C in the afternoon and slips back to 8°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 20°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11810
2189
3189
4189
5189
6179
7179
8179
9179
10178
11178
12168
13168
14168
15168
16168
17168
18158
19158
20157
21157
22157
23157
24147
25147
26147
27147
28147
29147
30146

How September really feels in Locarno

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.

Locarno weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -6°759.59.98.80.0
Feb / -5°638.88.9100.0
Mar / -2°9110.97.411.60.7
Apr10° / 14313.15.813.32.0
May14° / 16216.2214.73.7
Jun18° / 15515.50.515.55.2
Jul21° / 11°12814.20.215.25.9
Aug20° / 11°15813.60.1145.9
Sep16° / 17812.90.612.34.6
Oct11° / 18713.92.810.72.5
Nov / -1°17712.17.69.20.4
Dec / -5°8710.598.50.0

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 50%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15644
25644
35545
45545
55545
65545
75545
85446
95446
105446
115347
125347
135347
145248
155248
165149
175050
184951
194852
204852
214753
224753
234654
244555
254456
264456
274357
284357
294357
304258

Chance of precipitation in September

Any precipitationSnow

Locarno gets around 178 mm of rain and snow over 12.9 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 43% and peaks near 48% on the wettest days, and about 1 day brings snow.

0%20%40%60%151015202530
Rain chance (%)Snow chance (%)
1421
2421
3421
4421
5421
6421
7421
8421
9422
10422
11422
12432
13432
14432
15432
16432
17432
18432
19432
20432
21433
22443
23443
24453
25453
26464
27464
28474
29475
30485

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 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1919
2928
3937
4946
5955
6964
7973
8973
9982
10982
11991
12991
13991
14991
15991
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 4 km/h in September.

Across September, daily wind ranges from about 4 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
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

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 5:50 AM to 6:28 AM, and sunset from 6:59 PM to 6:00 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:506:59
213.15:516:57
313.05:536:55
413.05:546:53
512.95:556:51
612.95:566:49
712.85:586:47
812.85:596:45
912.76:006:43
1012.76:026:41
1112.66:036:39
1212.56:046:37
1312.56:066:35
1412.46:076:33
1512.46:086:31
1612.36:096:29
1712.36:116:27
1812.26:126:25
1912.26:136:23
2012.16:156:21
2112.06:166:19
2212.06:176:16
2311.96:196:14
2411.96:206:12
2511.86:216:10
2611.86:236:08
2711.76:246:06
2811.76:256:04
2911.66:276:02
3011.56:286:00

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 1.32 kWh/m² to a high of 5.8 kWh/m² in June across the year — September's 3.73 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.4Bright
24.3Bright
34.3Bright
44.3Bright
54.2Bright
64.2Bright
74.1Bright
84.1Bright
94.0Bright
104.0Moderate
113.9Moderate
123.9Moderate
133.8Moderate
143.8Moderate
153.7Moderate
163.7Moderate
173.6Moderate
183.6Moderate
193.5Moderate
203.5Moderate
213.4Moderate
223.4Moderate
233.3Moderate
243.3Moderate
253.2Moderate
263.2Moderate
273.1Moderate
283.1Moderate
293.0Moderate
303.0Moderate
Planning a trip in September

Is September a good time to visit Locarno?

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

4.6
Sightseeing
4th-best month of the year
0.7
Beach & pool
4th-best month of the year

September is a reasonable time to visit Locarno for sightseeing.

What to pack for Locarno in September

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

In September, Locarno sees daytime highs around 16°C and nights near 8°C. Worth packing: a warm layer and rain gear. About 13 days see rain.

a warm layerrain gear

UV index in Locarno 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 Locarno peaks around July 16 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 16UV 8Dec 21UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr6High
May7High
Jun7Very high
Jul8Very high
Aug7Very high
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Locarno 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 Locarno is worst in June — around 16 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (November, 6 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Locarno's WHO annual average of 10.5 µg/m³.

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJun 1615 µg/m³Nov 217 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb9Good
Mar13Moderate
Apr14Moderate
May12Moderate
Jun16Moderate
Jul13Moderate
Aug11Good
Sep9Good
Oct8Good
Nov6Good
Dec7Good
Location & terrain

Where is Locarno?

Locarno sits at 46.2°N, 8.8°E, 206 m above sea level, in Switzerland. The nearest listed city is Bellinzona, 17 km away.

LuganoPallanza-Intra-SunaVerbaniaVareseDomodossolaMalnateComo

Topography around Locarno

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

Within 3 km, the terrain around Locarno has very significant variations in elevation — a maximum elevation change of 1,412 m around an average of 433 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,216 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,405 m.

The land around Locarno is covered by trees (48%) and water (31%) within 3 km, trees (72%) within 16 km, and trees (48%) and grassland (27%) within 80 km.

3 km
1,412 m
16 km
2,216 m
80 km
4,405 m
treesgrasslandcroplandartificial surfacesbare terrainsnow and icewatermoss and lichen
September weather nearby: Bellinzona 17 km · Lugano 22 km · Pallanza-Intra-Suna 31 km · Verbania 34 km · Varese 39 km · Domodossola 39 km · Malnate 42 km · Como 46 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 Locarno (46.1709°, 8.7995°, elevation 206 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).