December weather forecastActon, CA
December
Weather in December
December, the first month of the winter in Acton, is also a moderate month, with an average temperature ranging between max 55.6°F (13.1°C) and min 39.2°F (4°C).Temperature
December, noted for its average high-temperature of 55.6°F (13.1°C) and an average low-temperature of 39.2°F (4°C), is considered the coldest month.Humidity
The months with the highest humidity in Acton are February, March and December, with an average relative humidity of 54%.Rainfall
The month with the most rainfall is December, when the rain falls for 6.3 days and typically aggregates up to 1.65" (42mm) of precipitation.Snowfall
Months with snowfall in Acton are January through April, November and December. December is the month with the most snowfall in Acton. Snow falls for 0.2 days and accumulates 3.23" (82mm) of snow.Daylight
The month with the shortest days in Acton is December, with an average of 9h and 54min of daylight.On the first day of the month, sunrise is at 6:41 am and sunset at 4:42 pm. On the last day of December, sunrise is at 6:59 am and sunset at 4:53 pm PST.
Sunshine
The average sunshine in December is 6.8h.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index in Acton, California. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: The daily high UV index of 3 in December translates into this advice:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Acton, CA
- Average high temperature in December: 55.6°F
The warmest month (with the highest average high temperature) is August (89.2°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in December: 39.2°F
The month with the highest average low temperature is August (63.1°F).
The coldest month (with the lowest average low temperature) is December (39.2°F).
Average pressure in December
Acton, CA
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in December
Acton, CA
- Average wind speed in December: 7.1mph
The windiest month (with the highest average wind speed) is April (7.6mph).
The calmest month (with the lowest average wind speed) is September (5.7mph).
Average humidity in December
Acton, CA
- Average humidity in December: 54%
The months with the highest relative humidity are February, March and December (54%).
The month with the lowest relative humidity is August (38%).
Average rainfall in December
Acton, CA
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in December
Acton, CA
- Average rainfall days in December: 6.3 days
The month with the highest number of rainy days is March (7.4 days).
The month with the least rainy days is June (1.2 days).
Average snowfall in December
Acton, CA
- Average snowfall in December: 3.23"
The month with the highest snowfall is December (3.23").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Acton, CA
- Average snowfall days in December: 0.2 days
The month with the highest number of snowfall days is February (0.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Acton, CA
- Average daylight in December: 9h and 54min
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 48min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 6h and 42min).
Average sunshine days in December
Acton, CA
- Average sunshine days in December: 23.6 days
The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (21.3 days).
Average UV index in December
Acton, CA
- Average UV index in December: 3
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 3).
Average cloud cover in December
Acton, CA
- Average cloud cover in December: 24
The months with the most cloud cover are March and December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in December
Acton, 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).
