January weather forecast
Mountain Brook, WA

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Weather in January

January, like December, in Mountain Brook, Washington, is a wintry winter month, with an average temperature fluctuating between 26.8°F (-2.9°C) and 36.7°F (2.6°C).

Temperature

A minor adjustment in Mountain Brook's average high-temperature is noted with the start of January, touching a still icy 36.7°F (2.6°C) from December's 35.2°F (1.8°C). Mountain Brook experiences an average low-temperature of 26.8°F (-2.9°C) in month of January.

Humidity

January, February and December, with an average relative humidity of 88%, are the most humid months in Mountain Brook, Washington.

Rainfall

The month with the most rainfall is January, when the rain falls for 17.1 days and typically aggregates up to 4.88" (124mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall in Mountain Brook. January is the month with the most snowfall in Mountain Brook, Washington. Snow falls for 5.3 days and accumulates 6.22" (158mm) of snow.

Daylight

In January, the average length of the day is 9h and 10min.
On the first day of January, sunrise is at 7:46 am and sunset at 4:31 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 5:09 pm PST.

Sunshine

January has the least sunshine of the year in Mountain Brook, with an average of 3.9h of sunshine.

UV index

January and February, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index of 1 during January translates into the following directions:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Updated: Feb 14, 2024 | Published by: Weather U.S. | About Us

Frequently asked questions

How cold is it in Mountain Brook in January?

The high-temperature, in January, in Mountain Brook, is 36.7°F (2.6°C), while the low-temperature averages to 26.8°F (-2.9°C).

What is the most humid month in Mountain Brook?

January, February and December, with an average relative humidity of 88%, are most humid months.

What is the average humidity in January in Mountain Brook?

In Mountain Brook, Washington, the average relative humidity in January is 88%.

What is the wettest month in Mountain Brook?

January is the month with the most rainfall. Rain falls for 17.1 days and accumulates 4.88" (124mm) of precipitation.

How many days does it rain in January in Mountain Brook?

In January, in Mountain Brook, Washington, the rain falls for 17.1 days. Throughout January, 4.88" (124mm) of precipitation is accumulated.

What is the snowiest month in Mountain Brook?

The month with the most snowfall in Mountain Brook, Washington, is January, when snow falls for 5.3 days and typically aggregates up to 6.22" (158mm) of snow.

How many days does it snow in January in Mountain Brook?

In Mountain Brook, Washington, in January, snow falls for 5.3 days, with typically accumulated 6.22" (158mm) of snow.

What is the average length of the day in January in Mountain Brook?

The average day length in January in Mountain Brook, Washington, is 9h and 10min.

What time are sunrise and sunset in January in Mountain Brook?

In January, on the first day of the month, sunrise is at 7:46 am and sunset at 4:31 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 5:09 pm PST.

What is the month with the least sunshine in Mountain Brook?

The month with the least sunshine in Mountain Brook, Washington, is January, with an average of 3.9h of sunshine.

How many hours of sunshine does Mountain Brook have in January?

In Mountain Brook, the average sunshine duration in January is 3.9h.

What is the month with the lowest UV index in Mountain Brook?

January and February, with an average maximum UV index of 1, are months with the lowest UV index in Mountain Brook, Washington.

What is the UV index reading in January in Mountain Brook?

In Mountain Brook, the average daily maximum UV index in January is 1. A UV Index value of 2, and less, symbolizes a low health threat from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Mountain Brook, WA

Average temperature in January - Mountain Brook, WA
  • Average high temperature in January: 36.7°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 January: 26.8°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 January
Mountain Brook, WA

Average pressure in January - Mountain Brook, WA
  • Average pressure in January: 30.15"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 January
Mountain Brook, WA

Average wind speed in January - Mountain Brook, WA
  • Average wind speed in January: 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 January
Mountain Brook, WA

Average humidity in January - Mountain Brook, WA
  • Average humidity in January: 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 January
Mountain Brook, WA

Average rainfall in January - Mountain Brook, WA
  • Average rainfall in January: 4.88"

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 January
Mountain Brook, WA

Average rainfall days in January - Mountain Brook, WA
  • Average rainfall days in January: 17.1 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 January
Mountain Brook, WA

Average snowfall in January - Mountain Brook, WA
  • Average snowfall in January: 6.22"

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 January
Mountain Brook, WA

Average snowfall days in January - Mountain Brook, WA
  • Average snowfall days in January: 5.3 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 January /
Average sunshine in January
Mountain Brook, WA

Average daylight in January / Average sunshine in January - Mountain Brook, WA
  • Average daylight in January: 9h and 1min

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 January: 3h and 5min

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 January
Mountain Brook, WA

Average sunshine days in January - Mountain Brook, WA
  • Average sunshine days in January: 10.3 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 January
Mountain Brook, WA

Average UV index in January - Mountain Brook, WA
  • Average UV index in January: 1

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 January
Mountain Brook, WA

Average cloud cover in January - Mountain Brook, WA
  • Average cloud cover in January: 61

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 January
Mountain Brook, WA

Average visibility in January - Mountain Brook, WA
  • Average visibility in January: 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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