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
The average high-temperature during September registers at a warm 85.3°F (29.6°C), closely corresponding to the preceding month. September in Brentwood, marked by an average low-temperature of 57.7°F (14.3°C), indicates a large temperature drop from the daytime peak.Heat index
September's mean heat index is evaluated at a hot 87.8°F (31°C). Ongoing activity coupled with exposure often results in weariness and could induce heat cramps.Take note of the fact that heat index values are based on shaded circumstances with light airflows. Exposure to the direct sun might augment heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. Additional elements encompassing metabolic differences, the degree of physical activity, and attire can impact the individual's perception of temperature. When in direct sunlight, one should be cautious as it can raise the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. Young ones often ignore the need to take a break and drink fluids. Thirst is a late-stage symptom of dehydration - hence, maintaining hydration, particularly during extended physical activities, is crucial.
Humidity
The least humid month is September, with an average relative humidity of 52%.Rainfall
In September, in Brentwood, the rain falls for 1.3 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. Throughout the year, in Brentwood, there are 62 rainfall days, and 10.16" (258mm) of precipitation is accumulated.Snowfall
In Brentwood, snow does not fall in January through November.Daylight
The average length of the day in September is 12h and 25min.On the first day of September in Brentwood, sunrise is at 6:37 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:50 pm PDT.
Sunshine
In Brentwood, California, the average sunshine in September is 11.2h.UV index
In Brentwood, California, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct 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
Is it hot in Brentwood during September?
What is the least humid month in Brentwood?
What is the average humidity in September in Brentwood?
How much does it rain in Brentwood in September?
When it does not snow in Brentwood?
What is the average length of the day in September in Brentwood?
When are sunrise and sunset in September in Brentwood?
How long on average sun shines in September in Brentwood?
What is the UV index intensity in September in Brentwood?
Average temperature in September
Brentwood, CA
- Average high temperature in September: 85.3°F
The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is December (55°F).
- Average low temperature in September: 57.7°F
The month with the highest average low temperature is September (57.7°F).
The coldest month (with the lowest average low temperature) is January (41.5°F).
Average pressure in September
Brentwood, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Brentwood, CA
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is June (7.8mph).
The calmest months (with the lowest average wind speed) are January and November (4.5mph).
Average humidity in September
Brentwood, CA
- Average humidity in September: 52%
The month with the highest relative humidity is January (74%).
The month with the lowest relative humidity is September (52%).
Average rainfall in September
Brentwood, 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
Brentwood, CA
- Average rainfall days in September: 1.3 days
The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is August (0.8 days).
Average snowfall days in September
Brentwood, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Brentwood, 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 36min).
- Average sunshine in September: 11h and 1min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
Brentwood, CA
- Average sunshine days in September: 28.5 days
The month with the most sunshine days is August (29.8 days).
The month with the least sunshine days is March (17.7 days).
Average UV index in September
Brentwood, CA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Brentwood, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 5).
Average visibility in September
Brentwood, 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).
Brentwood, California, USA
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