Monthly weather forecast and climate
Great Falls, MT

A far view from on top of the vast Missouri River of the City of Lights, Great Falls, Montana
A far view from on top of the vast Missouri River of the City of Lights, Great Falls, Montana

Weather in January

January is a wintry winter month in Great Falls, Montana, with average temperature ranging between min 19.8°F (-6.8°C) and max 32.4°F (0.2°C). In Great Falls, Montana, the average high-temperature is almost the same as in December - a cold 32.4°F (0.2°C). Weather in January »

Weather in February

February, the last month of the winter, in Great Falls, is also a subzero cold month, with average temperature fluctuating between 31.6°F (-0.2°C) and 18.3°F (-7.6°C). In February, the average high-temperature is almost the same as in January - a freezing cold 31.6°F (-0.2°C). Weather in February »

Weather in March

March, the first month of the spring, in Great Falls, is a chilly month, with average temperature varying between 43.3°F (6.3°C) and 27°F (-2.8°C). In March, the average high-temperature increases, from a freezing cold 31.6°F (-0.2°C) in February, to a frosty 43.3°F (6.3°C). Weather in March »

Weather in April

April is a fresh spring month in Great Falls, Montana, with temperature in the range of an average low of 34.9°F (1.6°C) and an average high of 52.3°F (11.3°C). In Great Falls, Montana, the average high-temperature rises, from a frosty 43.3°F (6.3°C) in March, to a cool 52.3°F (11.3°C). Weather in April »

Weather in May

May, the last month of the spring, in Great Falls, is a comfortable month, with average temperature varying between 42.6°F (5.9°C) and 63°F (17.2°C). In Great Falls, the average high-temperature rises, from a fresh 52.3°F (11.3°C) in April, to an enjoyable 63°F (17.2°C). Weather in May »

Weather in June

The first month of the summer, June, is an agreeable month in Great Falls, Montana, with temperature in the range of an average low of 49.5°F (9.7°C) and an average high of 72.1°F (22.3°C). In Great Falls, Montana, the average high-temperature in June increases, from an enjoyable 63°F (17.2°C) in May, to an agreeable 72.1°F (22.3°C). Weather in June »

Weather in July

July is a moderately hot summer month in Great Falls, Montana, with average temperature varying between 83.1°F (28.4°C) and 56.3°F (13.5°C). With an average high-temperature of 83.1°F (28.4°C) and an average low-temperature of 56.3°F (13.5°C), July is the warmest month. The average heat index in July is evaluated at 82.9°F (28.3°C). Weather in July »

Weather in August

The last month of the summer, August, is also a moderately hot month in Great Falls, Montana, with average temperature fluctuating between 57.7°F (14.3°C) and 81.9°F (27.7°C). In August, the average high-temperature is practically the same as in July - a still warm 81.9°F (27.7°C). Weather in August »

Weather in September

The first month of the autumn, September, is still a pleasant month in Great Falls, Montana, with temperature in the range of an average low of 50.5°F (10.3°C) and an average high of 71.2°F (21.8°C). In Great Falls, the average high-temperature decreases, from a moderately hot 81.9°F (27.7°C) in August, to an agreeable 71.2°F (21.8°C). Weather in September »

Weather in October

October, the same as September, is a cool autumn month in Great Falls, Montana, with average temperature ranging between max 54.5°F (12.5°C) and min 37.8°F (3.2°C). In Great Falls, the average high-temperature in October significantly decreases, from an agreeable 71.2°F (21.8°C) in September, to a cool 54.5°F (12.5°C). Weather in October »

Weather in November

The last month of the autumn, November, is also a wintry month in Great Falls, Montana, with temperature in the range of an average low of 27.3°F (-2.6°C) and an average high of 40.8°F (4.9°C). In November, the average high-temperature drops, from a cool 54.5°F (12.5°C) in October, to a cold 40.8°F (4.9°C). Weather in November »

Weather in December

December, the first month of the winter, in Great Falls, is still a freezing cold month, with average temperature ranging between max 30°F (-1.1°C) and min 18.3°F (-7.6°C). The coldest month is December, with an average high-temperature of 30°F (-1.1°C) and an average low-temperature of 18.3°F (-7.6°C). Weather in December »
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FAQ

What is the most humid month in Great Falls?

January is the most humid month, with an average relative humidity of 77%.

How much does it rain in Great Falls?

Throughout the year, there are 68.2 rainfall days, and 4.49" (114mm) of precipitation is accumulated.

When does it snow in Great Falls?

Months with snowfall in Great Falls, Montana, are January through May, September through December.

How much does it snow in Great Falls?

In Great Falls, during the entire year, snow falls for 45.4 days, and aggregates up to 11.61" (295mm) of snow.

What is the month with the least sunshine in Great Falls?

January, February and December, with an average of 5.5h of sunshine, are months with the least sunshine in Great Falls.

What are the months with the lowest UV index in Great Falls?

Months with the lowest UV index in Great Falls are January through March, October through December, with an average maximum UV index of 2.

When does it snow the most in Great Falls?

February is the month with the most snowfall in Great Falls. Snow falls for 10 days and accumulates 2.09" (53mm) of snow.

What is the rainiest month in Great Falls?

June is the month with the most rainfall in Great Falls, Montana. Rain falls for 8.6 days and accumulates 0.87" (22mm) of precipitation.

When it does not snow in Great Falls?

In Great Falls snow does not fall in June through August.

When are the longest days in Great Falls?

With an average of 15.9h of daylight, June has the longest days of the year in Great Falls, Montana.

What is the warmest month in Great Falls?

With an average high-temperature of 83.1°F (28.4°C) and an average low-temperature of 56.3°F (13.5°C), July is the warmest month in Great Falls, Montana.

What month has the most sunshine in Great Falls?

The month with the most sunshine is July, with an average of 12.1h of sunshine.

When is the highest UV index in Great Falls?

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

What is the least humid month in Great Falls?

August is the least humid month in Great Falls, with an average relative humidity of 40%.

What is the coldest month in Great Falls?

December is the coldest month, with an average high-temperature of 30°F (-1.1°C) and an average low-temperature of 18.3°F (-7.6°C).

What is the driest month in Great Falls?

The month with the least rainfall in Great Falls, Montana, is December when the rain falls for 2.7 days and typically collects 0.16" (4mm) of precipitation.

What is the month with the shortest days in Great Falls?

With an average of 8.5h of daylight, December has the shortest days of the year in Great Falls.

Average temperature
Great Falls, MT

Average temperature - Great Falls, MT

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is December (30°F).

The month with the highest average low temperature is August (57.7°F).
The coldest months (with the lowest average low temperature) are February and December (18.3°F).

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Average pressure
Great Falls, MT

Average pressure - Great Falls, MT

The month with the highest atmospheric pressure is January (30.14").
The month with the lowest atmospheric pressure is June (29.87").

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Average wind speed
Great Falls, MT

Average wind speed - Great Falls, MT

The windiest month (with the highest average wind speed) is November (11.4mph).
The calmest month (with the lowest average wind speed) is August (7.7mph).

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Average rainfall
Great Falls, MT

Average rainfall - Great Falls, MT

The wettest month (with the highest rainfall) is June (0.87").
The driest month (with the least rainfall) is December (0.16").

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Average rainfall days
Great Falls, MT

Average rainfall days - Great Falls, MT

The month with the highest number of rainy days is April (9.9 days).
The month with the least rainy days is December (2.7 days).

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Average snowfall
Great Falls, MT

Average snowfall - Great Falls, MT

The month with the highest snowfall is February (2.09").
Months with the least snowfall are June, July and August (0").

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Average snowfall days
Great Falls, MT

Average snowfall days - Great Falls, MT

The month with the highest number of snowfall days is February (10 days).
Months with the least snowfall days are June, July and August (0 days).

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Average daylight / Average sunshine
Great Falls, MT

Average daylight / Average sunshine - Great Falls, MT

The month with the longest days is June (Average daylight: 15.9h).
The month with the shortest days is December (Average daylight: 8.5h).

The month with the most sunshine is July (Average sunshine: 12.1h).
Months with the least sunshine are January, February and December (Average sunshine: 5.5).

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Average sunshine days
Great Falls, MT

Average sunshine days - Great Falls, MT

The month with the most sunshine days is July (26.1 days).
Months with the least sunshine days are February and April (16.2 days).

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Average UV index
Great Falls, MT

Average UV index - Great Falls, MT

The month with the highest UV index is July (UV index 6).
Months with the lowest UV index are January, February, March, October, November and December (UV index 2).

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Average visibility
Great Falls, MT

Average visibility - Great Falls, MT

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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