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
The coldest month is December, with an average high-temperature of 35.2°F (1.8°C) and an average low-temperature of 26.1°F (-3.3°C).Humidity
January, February and December, with an average relative humidity of 88%, are the most humid months.Rainfall
In Mountain Brook, during December, the rain falls for 16.1 days and regularly aggregates up to 4.61" (117mm) of precipitation. In Mountain Brook, during the entire year, the rain falls for 152.5 days and collects up to 26.93" (684mm) of precipitation.Snowfall
Months with snowfall in Mountain Brook are January through April, November and December. In Mountain Brook, during December, snow falls for 6.5 days and regularly aggregates up to 4.57" (116mm) of snow. Throughout the year, there are 23.9 snowfall days, and 18.74" (476mm) of snow is accumulated.Daylight
With an average of 8h and 42min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:27 am and sunset at 4:22 pm. On the last day of December, in Mountain Brook, sunrise is at 7:46 am and sunset at 4:31 pm PST.
Sunshine
In December, the average sunshine is 4h.UV index
In Mountain Brook, Washington, the average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV rays for average individuals.Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest in Mountain Brook?
How cold is it in Mountain Brook in December?
What is the most humid month in Mountain Brook?
What is the average humidity in December in Mountain Brook?
How much does it rain in Mountain Brook in December?
How much does it snow in Mountain Brook in December?
What is the month with the shortest days in Mountain Brook?
How many hours of daylight does Mountain Brook have in December?
What time are sunrise and sunset in December in Mountain Brook?
How long on average sun shines in December in Mountain Brook?
How high is the UV index in December in Mountain Brook?
Average temperature in December
Mountain Brook, WA
- Average high temperature in December: 35.2°F
The warmest month (with the highest average high temperature) is August (78.6°F).
The month with the lowest average high temperature is December (35.2°F).
- Average low temperature in December: 26.1°F
The month with the highest average low temperature is August (52.3°F).
The coldest month (with the lowest average low temperature) is December (26.1°F).
Average pressure in December
Mountain Brook, WA
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.97"Hg).
Average wind speed in December
Mountain Brook, WA
- Average wind speed in December: 5mph
The windiest month (with the highest average wind speed) is June (6.4mph).
The calmest month (with the lowest average wind speed) is October (4.8mph).
Average humidity in December
Mountain Brook, WA
- Average humidity in December: 88%
The months with the highest relative humidity are January, February and December (88%).
The months with the lowest relative humidity are July and August (58%).
Average rainfall in December
Mountain Brook, WA
- Average rainfall in December: 4.61"
The wettest month (with the highest rainfall) is January (4.88").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in December
Mountain Brook, WA
- Average rainfall days in December: 16.1 days
The month with the highest number of rainy days is March (19.4 days).
The month with the least rainy days is August (3.8 days).
Average snowfall in December
Mountain Brook, WA
- Average snowfall in December: 4.57"
The month with the highest snowfall is January (6.22").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Mountain Brook, WA
- Average snowfall days in December: 6.5 days
The month with the highest number of snowfall days is December (6.5 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
Mountain Brook, WA
- Average daylight in December: 8h and 4min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in December: 4h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in December
Mountain Brook, WA
- Average sunshine days in December: 9.9 days
The month with the most sunshine days is July (25.8 days).
The month with the least sunshine days is February (8.8 days).
Average UV index in December
Mountain Brook, WA
- Average UV index in December: 2
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and February (UV index 1).
Average cloud cover in December
Mountain Brook, WA
- Average cloud cover in December: 60
The months with the most cloud cover are January and February (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in December
Mountain Brook, WA
- Average visibility in December: 4mi
The months with the highest visibility are May, June, July, August and September (6mi).
The months with the lowest visibility are January, February and December (4mi).
Mountain Brook, Washington, USA
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