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 snowfall in December
- Average snowfall 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
In Swansea, California, December is the coldest month, with temperatures averaging a high of 46.9°F (8.3°C) and a low of 31.5°F (-0.3°C).Humidity
With an average relative humidity of 47%, December is the most humid month.Rainfall
December is the month with the most rainfall. Rain falls for 5.1 days and accumulates 0.67" (17mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. The month with the most snowfall in Swansea is December, when snow falls for 1.2 days and typically aggregates up to 1.18" (30mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 42min of daylight.On the first day of the month, sunrise is at 6:45 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:03 am and sunset at 4:46 pm PST.
Sunshine
January, February and December, with an average of 7.3h of sunshine, are months with the least sunshine in Swansea.UV index
The months with the lowest UV index are November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 2 in December interprets into the following recommendations:
Although prolonged sun exposure does not typically bother most people, children, babies, and those with sensitive skin should always have protection. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Frequently asked questions
What part of the year is the coldest in Swansea?
What is the temperature in December in Swansea?
What is the most humid month in Swansea?
What is the average humidity in December in Swansea?
What is the rainiest month in Swansea?
How much does it rain in Swansea in December?
When does it snow the most in Swansea?
How much does it snow in Swansea in December?
What is the month with the shortest days in Swansea?
What is the average length of the day in December in Swansea?
What time are sunrise and sunset in December in Swansea?
What are the months with the least sunshine in Swansea?
How many hours of sunshine does Swansea have in December?
When is the lowest UV index in Swansea?
What is the UV index reading in December in Swansea?
Average temperature in December
Swansea, CA
- Average high temperature in December: 46.9°F
The warmest month (with the highest average high temperature) is July (86°F).
The month with the lowest average high temperature is December (46.9°F).
- Average low temperature in December: 31.5°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is December (31.5°F).
Average pressure in December
Swansea, CA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).
Average wind speed in December
Swansea, CA
- Average wind speed in December: 6.2mph
The windiest months (with the highest average wind speed) are April, May and June (7.6mph).
The calmest month (with the lowest average wind speed) is November (5.8mph).
Average humidity in December
Swansea, CA
- Average humidity in December: 47%
The month with the highest relative humidity is December (47%).
The month with the lowest relative humidity is August (19%).
Average rainfall in December
Swansea, CA
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is December (0.67").
The driest months (with the least rainfall) are June and September (0.16").
Average rainfall days in December
Swansea, CA
- Average rainfall days in December: 5.1 days
The month with the highest number of rainy days is March (5.7 days).
The month with the least rainy days is September (2.3 days).
Average snowfall in December
Swansea, CA
- Average snowfall in December: 1.18"
The month with the highest snowfall is December (1.18").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Swansea, CA
- Average snowfall days in December: 1.2 days
The month with the highest number of snowfall days is December (1.2 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
Swansea, CA
- Average daylight in December: 9h and 4min
The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in December: 7h and 2min
The month with the most sunshine is June (Average sunshine: 12h and 12min).
The months with the least sunshine are January, February and December (Average sunshine: 7h and 18min).
Average sunshine days in December
Swansea, CA
- Average sunshine days in December: 25.3 days
The month with the most sunshine days is October (27.7 days).
The month with the least sunshine days is July (20 days).
Average UV index in December
Swansea, CA
- Average UV index in December: 2
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are November and December (UV index 2).
Average cloud cover in December
Swansea, CA
- Average cloud cover in December: 15
The month with the most cloud cover is January (Cloud cover 16).
The months with the least cloud cover are August and September (Cloud cover 5).
Average visibility in December
Swansea, 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).
Swansea, California, USA
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