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 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
The introduction of September notes a subtle temperature variation to a still moderately hot 81.1°F (27.3°C) from August's 82.9°F (28.3°C). Despite drastic daytime highs, Glen Ellen logs an average low-temperature reading of 54.7°F (12.6°C) throughout September.Heat index
Throughout September, the heat index is evaluated at 82.4°F (28°C). If activity and exposure persist, they could induce fatigue, leading to possible heat cramps.When assessing, remember that heat index measurements are for light winds and shaded spots. Facing direct sunlight may hike up the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', reflects the blend of air temperature and relative humidity to give a temperature impression. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. Direct sun exposure is noteworthy in its ability to escalate the felt temperature, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values hold particular significance for children. Young children are more at risk than adults since they tend to sweat less. Moreover, their large skin surface in proportion to their small bodies and the high heat production due to their activities contribute to their vulnerability.
Humidity
With an average relative humidity of 59%, September is the least humid month in Glen Ellen.Rainfall
In September, in Glen Ellen, the rain falls for 2.4 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. Throughout the year, in Glen Ellen, California, there are 73.3 rainfall days, and 15.47" (393mm) of precipitation is accumulated.Daylight
The average length of the day in September in Glen Ellen is 12h and 25min.On the first day of September in Glen Ellen, sunrise is at 6:40 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:53 pm PDT.
Sunshine
In September, the average sunshine is 11h.UV index
In September, the average daily maximum UV index in Glen Ellen is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: The UV index of 5 during September leads to these advisories:
Ensure safety - Recommendations to avert sunburn are presented. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Glen Ellen?
What is the least humid month in Glen Ellen?
What is the average humidity in September in Glen Ellen?
How many days does it rain in September in Glen Ellen?
What is the average length of the day in September in Glen Ellen?
When is the sunrise / sunset in September in Glen Ellen?
How many hours of sunshine does Glen Ellen have in September?
What is the UV index intensity in September in Glen Ellen?
Average temperature in September
Glen Ellen, CA
- Average high temperature in September: 81.1°F
The warmest month (with the highest average high temperature) is August (82.9°F).
The month with the lowest average high temperature is December (55°F).
- Average low temperature in September: 54.7°F
The month with the highest average low temperature is August (54.9°F).
The coldest month (with the lowest average low temperature) is December (41.4°F).
Average pressure in September
Glen Ellen, 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 June (29.91"Hg).
Average wind speed in September
Glen Ellen, CA
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is May (6.2mph).
The calmest month (with the lowest average wind speed) is November (4.4mph).
Average humidity in September
Glen Ellen, CA
- Average humidity in September: 59%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (59%).
Average rainfall in September
Glen Ellen, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (3.43").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Glen Ellen, CA
- Average rainfall days in September: 2.4 days
The month with the highest number of rainy days is March (13.4 days).
The month with the least rainy days is August (0.8 days).
Average daylight in September /
Average sunshine in September
Glen Ellen, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 11h and 0min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).
Average sunshine days in September
Glen Ellen, CA
- Average sunshine days in September: 26.7 days
The month with the most sunshine days is July (28.7 days).
The month with the least sunshine days is March (16.1 days).
Average UV index in September
Glen Ellen, CA
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Glen Ellen, CA
- Average cloud cover in September: 10
The month with the most cloud cover is March (Cloud cover 40).
The month with the least cloud cover is July (Cloud cover 8).
Average visibility in September
Glen Ellen, 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).
Glen Ellen, California, USA
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