September weather forecastInterlaken, CA
September
Weather in September
September, the first month of the autumn in Interlaken, is still a warm month, with an average temperature varying between 54.5°F (12.5°C) and 78.3°F (25.7°C).Temperature
The average high-temperature in September, at a still moderately hot 78.3°F (25.7°C), reveals a modest deviation from August's 78.6°F (25.9°C). Interlaken sees a consistent average low-temperature of 54.5°F (12.5°C) in September, indicating a substantial decrease from the day's temperature.Humidity
The months with the lowest humidity are September and October, with an average relative humidity of 64%.Rainfall
In Interlaken, in September, it is raining for 2.5 days, with typically 0.08" (2mm) of accumulated precipitation. In Interlaken, during the entire year, the rain falls for 67.1 days and collects up to 10.83" (275mm) of precipitation.Daylight
The average length of the day in September is 12h and 24min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:34 pm. On the last day of September, sunrise is at 7:02 am and sunset at 6:51 pm PDT.
Sunshine
In Interlaken, the average sunshine in September is 11.2h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum UV index of 5 in September translates into the following recommendations:
Put precautions into practice - Guidance to elude sunburn is provided. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Interlaken, CA
- Average high temperature in September: 78.3°F
The warmest month (with the highest average high temperature) is August (78.6°F).
The month with the lowest average high temperature is December (57.9°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is September (54.5°F).
The coldest months (with the lowest average low temperature) are February and March (43.2°F).
Average pressure in September
Interlaken, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in September
Interlaken, CA
- Average wind speed in September: 4.6mph
The windiest month (with the highest average wind speed) is May (5.9mph).
The calmest months (with the lowest average wind speed) are October and November (4.5mph).
Average humidity in September
Interlaken, CA
- Average humidity in September: 64%
The month with the highest relative humidity is March (75%).
The months with the lowest relative humidity are September and October (64%).
Average rainfall in September
Interlaken, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (2.09").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Interlaken, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (11.9 days).
The month with the least rainy days is August (0.8 days).
Average daylight in September /
Average sunshine in September
Interlaken, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 11h and 12min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).
Average sunshine days in September
Interlaken, CA
- Average sunshine days in September: 26.5 days
The month with the most sunshine days is August (28.9 days).
The month with the least sunshine days is March (17.8 days).
Average UV index in September
Interlaken, CA
- Average UV index in September: 5
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in September
Interlaken, CA
- Average cloud cover in September: 10
The month with the most cloud cover is March (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
Interlaken, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





