Climate and monthly 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). 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). Weather in January »

Weather in February

The last month of the winter, February, is also an icy month in Mountain Brook, Washington, with an average temperature ranging between min 27.7°F (-2.4°C) and max 38.3°F (3.5°C). Mountain Brook's entry into February measures an average high-temperature of a still cold 38.3°F (3.5°C), closely parallel to the preceding month. Weather in February »

Weather in March

The first month of the spring, March, is a frosty month in Mountain Brook, Washington, with temperature in the range of an average high of 44.1°F (6.7°C) and an average low of 30.6°F (-0.8°C). The start of March brings a subtle rise in the average high-temperature, moving from a cold 38.3°F (3.5°C) in February to a chilly 44.1°F (6.7°C). Weather in March »

Weather in April

April in Mountain Brook, Washington, is a cool spring month, with an average temperature ranging between max 52.5°F (11.4°C) and min 35.2°F (1.8°C). Mountain Brook observes a slight ascent in average high-temperatures during April, adjusting from a frosty 44.1°F (6.7°C) in March to a fresh 52.5°F (11.4°C). Weather in April »

Weather in May

May, the last month of the spring in Mountain Brook, is a refreshing month, with an average temperature varying between 41.4°F (5.2°C) and 62.8°F (17.1°C). An upsurge in temperatures occurs as April gives way to May, with average highs shifting from a fresh 52.5°F (11.4°C) to a refreshing 62.8°F (17.1°C). Weather in May »

Weather in June

The first month of the summer, June, is an agreeable month in Mountain Brook, Washington, with temperature in the range of an average low of 46°F (7.8°C) and an average high of 68.7°F (20.4°C). June's arrival brings a modest temperature shift, moving from an enjoyable 62.8°F (17.1°C) in May to a pleasant 68.7°F (20.4°C). Weather in June »

Weather in July

July in Mountain Brook, Washington, is a warm summer month, with an average temperature varying between 51.3°F (10.7°C) and 78.4°F (25.8°C). Mountain Brook, Washington, in July experiences an increase in the average high-temperature, moving from June's agreeable 68.7°F (20.4°C) to a warm 78.4°F (25.8°C). Weather in July »

Weather in August

The last month of the summer, August, is also a moderately hot month in Mountain Brook, Washington, with an average temperature varying between 52.3°F (11.3°C) and 78.6°F (25.9°C). In Mountain Brook, August is the month with the highest recorded average temperatures, measuring a high of 78.6°F (25.9°C) and a low of 52.3°F (11.3°C). Weather in August »

Weather in September

The first month of the autumn, September, is also an agreeable month in Mountain Brook, Washington, with temperature in the range of an average high of 69.1°F (20.6°C) and an average low of 47.7°F (8.7°C). With September's arrival, Mountain Brook, Washington, sees a decrease in average high-temperatures, moving from a moderately hot 78.6°F (25.9°C) in August to a pleasant 69.1°F (20.6°C). Weather in September »

Weather in October

October, like September, in Mountain Brook, Washington, is a cool autumn month, with an average temperature varying between 40.1°F (4.5°C) and 54.7°F (12.6°C). October signals a clear temperature drop, with average high-temperatures decreasing from September's agreeable 69.1°F (20.6°C) to a fresh 54.7°F (12.6°C). Weather in October »

Weather in November

The last month of the autumn, November, is also a frosty month in Mountain Brook, Washington, with an average temperature ranging between max 43°F (6.1°C) and min 32.9°F (0.5°C). Mountain Brook experiences a temperature shift at the start of November, with average high-temperatures adjusting from a cool 54.7°F (12.6°C) in October to a frosty 43°F (6.1°C). Weather in November »

Weather in December

The first month of the winter, December, is also an icy month in Mountain Brook, Washington, with an average temperature varying between 26.1°F (-3.3°C) and 35.2°F (1.8°C). 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). Weather in December »
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the most humid month in Mountain Brook?

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

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 Mountain Brook?

In Mountain Brook, Washington, during the entire year, the rain falls for 152.5 days and collects up to 26.93" (684mm) of precipitation.

When does it snow in Mountain Brook?

January through April, November and December are months with snowfall in Mountain Brook, Washington.

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 much does it snow in Mountain Brook?

Throughout the year, in Mountain Brook, Washington, there are 23.9 snowfall days, and 18.74" (476mm) of snow is accumulated.

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.

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.

When is Daylight Saving Time (DST) in Mountain Brook?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.

When it does not snow in Mountain Brook?

In Mountain Brook, Washington, snow does not fall in May through October.

When are the longest days in Mountain Brook?

The month with the longest days in Mountain Brook, Washington, is June, with an average of 15h and 42min of daylight.

What is the least humid month in Mountain Brook?

The months with the lowest humidity are July and August, with an average relative humidity of 58%.

What is the driest month in Mountain Brook?

The month with the least rainfall in Mountain Brook is July, when the rain falls for 3.9 days and typically collects 0.24" (6mm) of precipitation.

What month has the most sunshine in Mountain Brook?

The month with the most sunshine in Mountain Brook, Washington, is July, with an average of 11.8h of sunshine.

When is the highest UV index in Mountain Brook?

July is the month with the highest UV index, with an average maximum UV index of 6.

What is the warmest month in Mountain Brook?

August, recording an average high temperature of 78.6°F (25.9°C) and a low temperature of 52.3°F (11.3°C), is Mountain Brook's warmest month.

What part of the year is the coldest in Mountain Brook?

December is the month when Mountain Brook, Washington, experiences its coldest temperatures, averaging a high of 35.2°F (1.8°C) and a low of 26.1°F (-3.3°C).

What is the month with the shortest days in Mountain Brook?

December has the shortest days of the year, with an average of 8h and 42min of daylight.

Average temperature
Mountain Brook, WA

Average temperature - Mountain Brook, WA

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).

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
Mountain Brook, WA

Average pressure - Mountain Brook, WA

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
Mountain Brook, WA

Average wind speed - Mountain Brook, WA

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
Mountain Brook, WA

Average humidity - Mountain Brook, WA

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
Mountain Brook, WA

Average rainfall - Mountain Brook, WA

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
Mountain Brook, WA

Average rainfall days - Mountain Brook, WA

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
Mountain Brook, WA

Average snowfall - Mountain Brook, WA

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
Mountain Brook, WA

Average snowfall days - Mountain Brook, WA

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 / Average sunshine
Mountain Brook, WA

Average daylight / Average sunshine - Mountain Brook, WA

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).

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
Mountain Brook, WA

Average sunshine days - Mountain Brook, WA

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 cloud cover
Mountain Brook, WA

Average cloud cover - Mountain Brook, WA

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
Mountain Brook, WA

Average visibility - Mountain Brook, WA

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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