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
As Westmont steps into September, the average high-temperature is measured at a still warm 79.7°F (26.5°C), displaying minor differences from August's 80.2°F (26.8°C). During the nights in September, Westmont observes an average low-temperature of 64.2°F (17.9°C).Humidity
In Westmont, the average relative humidity in September is 62%.Rainfall
In Westmont, in September, it is raining for 3.2 days, with typically 0.24" (6mm) of accumulated precipitation. In Westmont, during the entire year, the rain falls for 47.6 days and collects up to 7.24" (184mm) of precipitation.Daylight
In Westmont, California, the average length of the day in September is 12h and 22min.On the first day of September in Westmont, sunrise is at 6:27 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:38 pm PDT.
Sunshine
In September, the average sunshine is 10.5h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index in Westmont. A UV Index value of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for average individuals.Note: The daily high UV index of 6 during September translates into the following recommendations:
Adhere to precautions and respect sun safety doctrines. Avoiding sunburn is vital. UV radiation from the sun is at its strongest between 10 a.m. and 4 p.m. Try to limit direct exposure during these hours. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Frequently asked questions
What are September temperatures in Westmont?
What is the average humidity in September in Westmont?
How much does it rain in Westmont in September?
What is the average length of the day in September in Westmont?
When is the sunrise / sunset in September in Westmont?
How many hours of sunshine does Westmont have in September?
What are the months with the highest UV index in Westmont?
What is the UV index intensity in September in Westmont?
Average temperature in September
Westmont, CA
- Average high temperature in September: 79.7°F
The warmest month (with the highest average high temperature) is August (80.2°F).
The month with the lowest average high temperature is December (64°F).
- Average low temperature in September: 64.2°F
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (51.1°F).
Average pressure in September
Westmont, CA
- Average pressure in September: 29.9"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Westmont, CA
- Average wind speed in September: 4.9mph
The windiest month (with the highest average wind speed) is April (6.4mph).
The calmest month (with the lowest average wind speed) is September (4.9mph).
Average humidity in September
Westmont, CA
- Average humidity in September: 62%
The month with the highest relative humidity is June (70%).
The month with the lowest relative humidity is November (54%).
Average rainfall in September
Westmont, CA
- Average rainfall in September: 0.24"
The wettest month (with the highest rainfall) is January (1.42").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
Westmont, CA
- Average rainfall days in September: 3.2 days
The month with the highest number of rainy days is March (6.5 days).
The month with the least rainy days is June (1.7 days).
Average daylight in September /
Average sunshine in September
Westmont, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 3min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
Westmont, CA
- Average sunshine days in September: 23.4 days
The month with the most sunshine days is October (25.5 days).
The month with the least sunshine days is June (21.4 days).
Average UV index in September
Westmont, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).
Average cloud cover in September
Westmont, CA
- Average cloud cover in September: 11
The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 7).
Average visibility in September
Westmont, 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).
Westmont, California, USA
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