September weather forecastJanesville, CA
September
Weather in September
September, the first month of the autumn in Janesville, is still a warm month, with temperature in the range of an average high of 74.3°F (23.5°C) and an average low of 46.4°F (8°C).Temperature
September comes with a decrease in the average high-temperature, falling from 83.5°F (28.6°C) in August to a still warm 74.3°F (23.5°C). Contrary to the day's heat, an average low-temperature of 46.4°F (8°C) is recorded during the nights in September in Janesville.Humidity
The average relative humidity in September is 40%.Rainfall
In Janesville, in September, it is raining for 4.5 days, with typically 0.31" (8mm) of accumulated precipitation. Throughout the year, in Janesville, there are 97.2 rainfall days, and 13.98" (355mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows in Janesville, California. Throughout September, in the average 0.2 snowfall days, it receives 0.08" (2mm) of snow. Throughout the year, there are 52.5 snowfall days, and 43.07" (1094mm) of snow is accumulated.Daylight
In Janesville, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:33 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:45 pm PDT.
Sunshine
In September, the average sunshine in Janesville, California, is 11.3h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: The maximum daily UV index of 4 during September translates into the following directions:
Take necessary precautions - Defending against sun damage is advocated. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Attention! Nearly twice the Sun's UV radiation can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Janesville, CA
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (84.6°F).
The month with the lowest average high temperature is December (36.9°F).
- Average low temperature in September: 46.4°F
The month with the highest average low temperature is July (52.7°F).
The coldest month (with the lowest average low temperature) is December (22.6°F).
Average pressure in September
Janesville, CA
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.2"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Janesville, CA
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is April (7.2mph).
The calmest month (with the lowest average wind speed) is January (5.2mph).
Average humidity in September
Janesville, CA
- Average humidity in September: 40%
The month with the highest relative humidity is January (81%).
The months with the lowest relative humidity are July and August (35%).
Average rainfall in September
Janesville, CA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is December (2.28").
The driest month (with the least rainfall) is July (0.12").
Average rainfall days in September
Janesville, CA
- Average rainfall days in September: 4.5 days
The month with the highest number of rainy days is March (13.4 days).
The months with the least rainy days are July and August (2.8 days).
Average snowfall in September
Janesville, CA
- Average snowfall in September: 0.08"
The month with the highest snowfall is December (10.16").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Janesville, CA
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (11.4 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Janesville, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 11h and 18min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are January and December (Average sunshine: 5h and 48min).
Average sunshine days in September
Janesville, CA
- Average sunshine days in September: 24.7 days
The month with the most sunshine days is August (26.2 days).
The month with the least sunshine days is March (12 days).
Average UV index in September
Janesville, CA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are February and November (UV index 1).
Average cloud cover in September
Janesville, CA
- Average cloud cover in September: 10
The month with the most cloud cover is December (Cloud cover 38).
The months with the least cloud cover are July and August (Cloud cover 7).
Average visibility in September
Janesville, CA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).
