Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The month of December, characterized by an average high of 64°F (17.8°C) and a low of 51.4°F (10.8°C), is recognized as the coldest.Humidity
In December, the average relative humidity in Westmont is 56%.Rainfall
In Westmont, in December, during 5 rainfall days, 1.3" (33mm) of precipitation is typically accumulated. In Westmont, California, during the entire year, the rain falls for 47.6 days and collects up to 7.24" (184mm) of precipitation.Daylight
The month with the shortest days in Westmont, California, is December, with an average of 9h and 54min of daylight.On the first day of December in Westmont, sunrise is at 6:40 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 4:54 pm PST.
Sunshine
December has the least sunshine of the year in Westmont, with an average of 6.7h of sunshine.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: A daily maximum UV index of 4 in December translates into the following instructions:
Undertake precautions - Obligation exists to protect against skin and eye damage. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Frequently asked questions
What are the coldest months in Westmont?
What is the temperature in December in Westmont?
What is the average humidity in December in Westmont?
How many days does it rain in December in Westmont?
What is the month with the shortest days in Westmont?
What is the average length of the day in December in Westmont?
When are sunrise and sunset in December in Westmont?
What is the month with the least sunshine in Westmont?
How many hours of sunshine does Westmont have in December?
What are the months with the lowest UV index in Westmont?
What is the UV index intensity in December in Westmont?
Average temperature in December
Westmont, CA
- Average high temperature in December: 64°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 December: 51.4°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 December
Westmont, CA
- Average pressure in December: 30.07"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 December
Westmont, CA
- Average wind speed in December: 5.5mph
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 December
Westmont, CA
- Average humidity in December: 56%
The month with the highest relative humidity is June (70%).
The month with the lowest relative humidity is November (54%).
Average rainfall in December
Westmont, CA
- Average rainfall in December: 1.3"
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 December
Westmont, CA
- Average rainfall days in December: 5 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 December /
Average sunshine in December
Westmont, CA
- Average daylight in December: 9h and 5min
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 December: 6h and 4min
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 December
Westmont, CA
- Average sunshine days in December: 24.8 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 December
Westmont, CA
- Average UV index in December: 4
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 December
Westmont, CA
- Average cloud cover in December: 22
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 December
Westmont, CA
- Average visibility in December: 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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