Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
Island Mountain's warmest month, September, registers temperatures that range from a high of 69.8°F (21°C) to a low of 54.3°F (12.4°C).Humidity
September is the least humid month, with an average relative humidity of 72%.Rainfall
In September, the rain falls for 3.5 days. Throughout September, 0.47" (12mm) of precipitation is accumulated. In Island Mountain, during the entire year, the rain falls for 102.7 days and collects up to 28.78" (731mm) of precipitation.Snowfall
In Island Mountain, snow does not fall in January, March through December.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, sunrise is at 6:42 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:57 pm PDT.
Sunshine
The average sunshine in September is 10.4h.UV index
In Island Mountain, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Make use of precautions - It is urged to ward off sun damage. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What month is the hottest?
What are the temperatures in September?
What is the least humid month?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
How many hours of daylight does Island Mountain have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Island Mountain, CA
- Average high temperature in September: 69.8°F
The warmest month (with the highest average high temperature) is September (69.8°F).
The month with the lowest average high temperature is December (53.4°F).
- Average low temperature in September: 54.3°F
The months with the highest average low temperature are July, August and September (54.3°F).
The coldest month (with the lowest average low temperature) is February (43.5°F).
Average pressure in September
Island Mountain, CA
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are August and September (29.95"Hg).
Average wind speed in September
Island Mountain, CA
- Average wind speed in September: 8.1mph
The windiest month (with the highest average wind speed) is June (10.6mph).
The calmest months (with the lowest average wind speed) are January and August (7.8mph).
Average humidity in September
Island Mountain, CA
- Average humidity in September: 72%
The month with the highest relative humidity is March (81%).
The month with the lowest relative humidity is September (72%).
Average rainfall in September
Island Mountain, CA
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is December (5.31").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in September
Island Mountain, CA
- Average rainfall days in September: 3.5 days
The month with the highest number of rainy days is March (16.4 days).
The month with the least rainy days is August (1.8 days).
Average snowfall days in September
Island Mountain, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Island Mountain, CA
- Average daylight in September: 12h and 2min
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: 10h and 2min
The months with the most sunshine are July and August (Average sunshine: 11h and 42min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).
Average sunshine days in September
Island Mountain, CA
- Average sunshine days in September: 25.9 days
The month with the most sunshine days is July (28.4 days).
The month with the least sunshine days is March (13.1 days).
Average UV index in September
Island Mountain, CA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 3).
Average cloud cover in September
Island Mountain, CA
- Average cloud cover in September: 14
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 10).
Average visibility in September
Island Mountain, 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).
Island Mountain, California, USA
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