September weather forecast
L'Isle, Switzerland

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September

Weather in September

The first month of the autumn, September, is still a refreshing month in L'Isle, Switzerland, with an average temperature ranging between max 18.4°C (65.1°F) and min 9.5°C (49.1°F).

Temperature

The move into September indicates a slight reduction in the average high-temperature, down from August's pleasant 22.1°C (71.8°F) to an enjoyable 18.4°C (65.1°F). During the nights in September, L'Isle experiences a consistent average temperature of 9.5°C (49.1°F).

Humidity

In L'Isle, the average relative humidity in September is 79%.

Rainfall

The month with the least rainfall is September, when the rain falls for 13 days and typically collects 47mm (1.85") of precipitation.

Snowfall

In L'Isle, snow does not fall in June through September.

Daylight

In September, the average length of the day is 12h and 33min.
On the first day of September, sunrise is at 06:54 and sunset at 20:13. On the last day of the month, sunrise is at 07:32 and sunset at 19:16 CEST.

Sunshine

In L'Isle, the average sunshine in September is 9h.

UV index

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The maximum UV index of 4 during September translates into these guidelines:
Make use of precautions - Shielding skin and eyes from injury is a requirement. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Updated: Feb 4, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures in L'Isle?
An average high-temperature, in September, in L'Isle, is 18.4°C (65.1°F) and the average low-temperature is 9.5°C (49.1°F).
What is the average humidity in September in L'Isle?
In September, the average relative humidity is 79%.
What is the driest month in L'Isle?
September is the month with the least rainfall. Rain falls for 13 days and accumulates 47mm (1.85") of precipitation.
How much does it rain in L'Isle in September?
In L'Isle, Switzerland, in September, it is raining for 13 days, with typically 47mm (1.85") of accumulated precipitation.
When it does not snow in L'Isle?
June through September are months without snowfall in L'Isle, Switzerland.
Does it snow in L'Isle in September?
In L'Isle, in September, it doesn't snow. In October, it regularly snows.
What is the average length of the day in September in L'Isle?
In September, the average day length in L'Isle, Switzerland, is 12h and 33min.
When is the sunrise / sunset in September in L'Isle?
In September, on the first day of the month, sunrise is at 06:54 and sunset at 20:13. On the last day of the month, in L'Isle, sunrise is at 07:32 and sunset at 19:16 CEST.
How long on average sun shines in September in L'Isle?
In September, the average sunshine duration in L'Isle, Switzerland, is 9h.
How high is the UV index in September in L'Isle?
In September, the average daily maximum UV index in L'Isle is 4. A UV Index of 3 to 5 symbolizes a moderate health threat from unprotected exposure to UV radiation.
Today
Tomorrow
Long-term
YearJFMAMJJASeptemberOND
Aug
September
Oct
Average high temperature
22.1°C
18.4°C
13.8°C
Average low temperature
12.5°C
9.5°C
5.7°C
Average pressure
1017.8mbar
1018.5mbar
1018.2mbar
Average wind speed
7km/h
8.4km/h
9km/h
Average max. wind speed
8.1km/h
9.6km/h
10.3km/h
Average wind speed gusts
11.2km/h
13.5km/h
14.6km/h
Average humidity
77%
79%
78%
Average rainfall
84mm
47mm
72mm
Average rainfall days
16.9
13
13.6
Average snowfall
0mm
0mm
5mm
Average snowfall days
0
0
0.4
Average daylight
14h 1min
12h 3min
10h 5min
Average sunshine
10h 4min
9h 0min
6h 5min
Average sunshine days
9.2
13.8
15.4
Average UV index
4
4
3
Average cloud cover
29%
31%
33%
Average visibility
9km
9km
9km
Average temperature in September
L'Isle, Switzerland
  • Average high temperature in September: 18.4°C

The warmest months (with the highest average high temperature) are July and August (22.1°C).
The month with the lowest average high temperature is January (3.2°C).

  • Average low temperature in September: 9.5°C

The month with the highest average low temperature is July (12.6°C).
The coldest month (with the lowest average low temperature) is January (-2.3°C).

Average pressure in September
L'Isle, Switzerland
  • Average pressure in September: 1018.5mbar

The month with the highest atmospheric pressure is December (1021.2mbar).
The month with the lowest atmospheric pressure is April (1015.5mbar).

Average wind speed in September
L'Isle, Switzerland
  • Average wind speed in September: 8.4km/h

The windiest month (with the highest average wind speed) is February (12.1km/h).
The calmest month (with the lowest average wind speed) is August (7km/h).

Average humidity in September
L'Isle, Switzerland
  • Average humidity in September: 79%

The month with the highest relative humidity is January (82%).
The months with the lowest relative humidity are April, July and August (77%).

Average rainfall in September
L'Isle, Switzerland
  • Average rainfall in September: 47mm

The wettest month (with the highest rainfall) is December (92mm).
The driest month (with the least rainfall) is September (47mm).

Average rainfall days in September
L'Isle, Switzerland
  • Average rainfall days in September: 13 days

The month with the highest number of rainy days is June (20 days).
The month with the least rainy days is February (11.8 days).

Average snowfall in September
L'Isle, Switzerland
  • Average snowfall in September: 0mm

The month with the highest snowfall is December (193mm).
The months with the least snowfall are June, July, August and September (0mm).

Average snowfall days in September
L'Isle, Switzerland
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
L'Isle, Switzerland
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).

  • Average sunshine in September: 9h and 0min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

Average sunshine days in September
L'Isle, Switzerland
  • Average sunshine days in September: 13.8 days

The month with the most sunshine days is October (15.4 days).
The month with the least sunshine days is June (6.7 days).

Average UV index in September
L'Isle, Switzerland
  • Average UV index in September: 4

The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
L'Isle, Switzerland
  • Average cloud cover in September: 31

The month with the most cloud cover is January (Cloud cover 41).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in September
L'Isle, Switzerland
  • Average visibility in September: 9km

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).

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