December weather forecastMountain Brook, AL
December
Weather in December
Bringing the year to a close, December starts to feel like winter in Mountain Brook. With an average high temperature of 54.5°F (12.5°C) and a low of 39.9°F (4.4°C), the difference from November's weather is clearly noticeable. The month witnesses an increase in relative humidity to 79%, the highest for the year. Despite the colder weather and fewer daylight hours, the city teems with warmth from holiday festivities and snowy landscapes. As Christmas spirit and cheerful lights fill the air, December is a delightfully festive time to visit Mountain Brook.Temperature
December's arrival aligns with a minor decrease in average high-temperatures, from November's enjoyable 61.9°F (16.6°C) to a fresh 54.5°F (12.5°C). Mountain Brook, during the month of December, experiences an average low-temperature of 39.9°F (4.4°C).Humidity
With an average relative humidity of 79%, December is the most humid month.Rainfall
In December, in Mountain Brook, the rain falls for 10.6 days. Throughout December, 1.89" (48mm) of precipitation is accumulated. Throughout the year, there are 143.1 rainfall days, and 18.58" (472mm) of precipitation is accumulated.Snowfall
January through March, November and December are months with snowfall. In December, it is snowing for 0.4 days. Throughout December, 0.08" (2mm) of snow is accumulated. Throughout the year, there are 2.5 snowfall days, and 0.35" (9mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 10h and 0min of daylight.On the first day of the month, sunrise is at 6:33 am and sunset at 4:38 pm. On the last day of December, sunrise is at 6:51 am and sunset at 4:49 pm CST.
Sunshine
In December, the average sunshine is 4.9h.UV index
With an average maximum UV index of 2, December is the month with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 2 in December converts into the following recommendations:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. To protect against the Sun's most potent rays, avoid direct exposure around midday. During bright days, sunglasses that offer UVA and UVB defense are recommended. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Mountain Brook, AL
- Average high temperature in December: 54.5°F
The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (50.7°F).
- Average low temperature in December: 39.9°F
The month with the highest average low temperature is July (71.1°F).
The coldest month (with the lowest average low temperature) is January (35.2°F).
Average pressure in December
Mountain Brook, AL
- Average pressure in December: 30.15"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in December
Mountain Brook, AL
- Average wind speed in December: 7mph
The windiest month (with the highest average wind speed) is February (7.4mph).
The calmest months (with the lowest average wind speed) are July and August (4.5mph).
Average humidity in December
Mountain Brook, AL
- Average humidity in December: 79%
The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Mountain Brook, AL
- Average rainfall in December: 1.89"
The wettest month (with the highest rainfall) is June (1.97").
The driest month (with the least rainfall) is November (1.02").
Average rainfall days in December
Mountain Brook, AL
- Average rainfall days in December: 10.6 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is November (7.9 days).
Average snowfall in December
Mountain Brook, AL
- Average snowfall in December: 0.08"
The month with the highest snowfall is January (0.12").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Mountain Brook, AL
- Average snowfall days in December: 0.4 days
The months with the highest number of snowfall days are January and February (0.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Mountain Brook, AL
- Average daylight in December: 10h and 0min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in December: 4h and 54min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in December
Mountain Brook, AL
- Average sunshine days in December: 17.5 days
The month with the most sunshine days is October (20.9 days).
The month with the least sunshine days is July (11.1 days).
Average UV index in December
Mountain Brook, AL
- Average UV index in December: 2
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 2).
Average cloud cover in December
Mountain Brook, AL
- Average cloud cover in December: 47
The month with the most cloud cover is February (Cloud cover 48).
The months with the least cloud cover are June and September (Cloud cover 30).
Average visibility in December
Mountain Brook, AL
- 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).
