Monthly weather forecast and climate
Boulder, MT

January, the same as December, in Boulder, Montana, is another subzero cold winter month, with average temperature varying between 14.5°F (-9.7°C) and 29.7°F (-1.3°C). In Boulder, the average high-temperature in January is practically the same as in December - a still freezing cold 29.7°F (-1.3°C). Weather in January »

The last month of the winter, February, is also a subzero cold month in Boulder, Montana, with average temperature ranging between min 13.5°F (-10.3°C) and max 29.3°F (-1.5°C). In February, the average high-temperature is almost the same as in January - a still freezing cold 29.3°F (-1.5°C). Weather in February »

The first month of the spring, March, is a wintry month in Boulder, Montana, with temperature in the range of an average low of 21.6°F (-5.8°C) and an average high of 38.7°F (3.7°C). In Boulder, the average high-temperature in March rises, from a freezing cold 29.3°F (-1.5°C) in February, to a cold 38.7°F (3.7°C). Weather in March »

April in Boulder, Montana, is a chilly spring month, with average temperature fluctuating between 27°F (-2.8°C) and 46.4°F (8°C). In April, the average high-temperature slightly increases, from a wintry 38.7°F (3.7°C) in March, to a chilly 46.4°F (8°C). Weather in April »

May, the last month of the spring, in Boulder, is a mild month, with temperature in the range of an average low of 35.2°F (1.8°C) and an average high of 58.5°F (14.7°C). In May, the average high-temperature rises, from a frosty 46.4°F (8°C) in April, to a moderate 58.5°F (14.7°C). Weather in May »

The first month of the summer, June, is an agreeable month in Boulder, Montana, with average temperature varying between 68.5°F (20.3°C) and 42.4°F (5.8°C). In June, the average high-temperature rises, from a mild 58.5°F (14.7°C) in May, to an agreeable 68.5°F (20.3°C). Weather in June »

July is a warm summer month in Boulder, Montana, with average temperature ranging between min 48.4°F (9.1°C) and max 79.7°F (26.5°C). With an average high-temperature of 79.7°F (26.5°C) and an average low-temperature of 48.4°F (9.1°C), July is the warmest month. Weather in July »

August, the last month of the summer, in Boulder, is another warm month, with average temperature varying between 77.5°F (25.3°C) and 48.6°F (9.2°C). In August, the average high-temperature is almost the same as in July - a still warm 77.5°F (25.3°C). Weather in August »

September, the first month of the autumn, in Boulder, is still a comfortable month, with average temperature ranging between max 67.5°F (19.7°C) and min 42.4°F (5.8°C). In Boulder, the average high-temperature decreases, from a moderately hot 77.5°F (25.3°C) in August, to an enjoyable 67.5°F (19.7°C). Weather in September »

October, the same as September, is another fresh autumn month in Boulder, Montana, with average temperature varying between 50.9°F (10.5°C) and 31.3°F (-0.4°C). In Boulder, the average high-temperature significantly decreases, from a comfortable 67.5°F (19.7°C) in September, to a cool 50.9°F (10.5°C). Weather in October »

The last month of the autumn, November, is also a wintry month in Boulder, Montana, with temperature in the range of an average low of 21.2°F (-6°C) and an average high of 36.9°F (2.7°C). In November, the average high-temperature drops, from a fresh 50.9°F (10.5°C) in October, to a wintry 36.9°F (2.7°C). Weather in November »

December, the first month of the winter, in Boulder, is still a freezing cold month, with average temperature ranging between min 12.6°F (-10.8°C) and max 27°F (-2.8°C). The coldest month is December, with an average high-temperature of 27°F (-2.8°C) and an average low-temperature of 12.6°F (-10.8°C). Weather in December »

What is the most humid month in Boulder?

January is the most humid month in Boulder, Montana, with an average relative humidity of 86%.

How many days does it rain in Boulder?

In Boulder, Montana, during the entire year, the rain falls for 133.7 days and collects up to 16.38" (416mm) of precipitation.

When does it snow in Boulder?

Months with snowfall in Boulder are January through June, September through December.

How much does it snow in Boulder?

In Boulder, Montana, during the entire year, snow falls for 105.8 days, and aggregates up to 55.12" (1400mm) of snow.

What is the month with the least sunshine in Boulder?

January and December, with an average of 5.6h of sunshine, are months with the least sunshine.

When does it snow the most in Boulder?

The month with the most snowfall is February when snow falls for 18 days and typically aggregates up to 9.72" (247mm) of snow.

When is the lowest UV index in Boulder?

The month with the lowest UV index in Boulder is February, with an average maximum UV index of 1.

What is the rainiest month in Boulder?

June is the month with the most rainfall in Boulder, Montana. Rain falls for 16 days and accumulates 2.68" (68mm) of precipitation.

When are the longest days in Boulder?

With an average of 15.7h of daylight, June has the longest days of the year in Boulder, Montana.

What is the warmest month in Boulder?

With an average high-temperature of 79.7°F (26.5°C) and an average low-temperature of 48.4°F (9.1°C), July is the warmest month in Boulder, Montana.

When it does not snow in Boulder?

In Boulder snow does not fall in July and August.

What month has the most sunshine in Boulder?

The month with the most sunshine in Boulder, Montana, is July, with an average of 11.7h of sunshine.

What is the month with the highest UV index in Boulder?

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

What is the least humid month in Boulder?

August is the least humid month, with an average relative humidity of 46%.

What is the coldest month in Boulder?

December is the coldest month, with an average high-temperature of 27°F (-2.8°C) and an average low-temperature of 12.6°F (-10.8°C).

What is the driest month in Boulder?

The month with the least rainfall in Boulder is December when the rain falls for 8.2 days and typically collects 0.79" (20mm) of precipitation.

What is the month with the shortest days in Boulder?

With an average of 8.7h of daylight, December has the shortest days of the year in Boulder, Montana.
Average temperature - Boulder, MT
Average pressure - Boulder, MT

The month with the highest atmospheric pressure is January (30.19").
The month with the lowest atmospheric pressure is June (29.91").

Average wind speed - Boulder, MT

The windiest months (with the highest average wind speed) are January and November (6.5mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).

Average rainfall - Boulder, MT

The wettest month (with the highest rainfall) is June (2.68").
The driest month (with the least rainfall) is December (0.79").

Average rainfall days - Boulder, MT
Average snowfall - Boulder, MT
Average snowfall days - Boulder, MT

The month with the highest number of snowfall days is February (18 days).
Months with the least snowfall days are July and August (0 days).

Average daylight / Average sunshine - Boulder, MT

The month with the longest days is June (Average daylight: 15.7h).
The month with the shortest days is December (Average daylight: 8.7h).

The month with the most sunshine is July (Average sunshine: 11.7h).
Months with the least sunshine are January and December (Average sunshine: 5.6).

Average sunshine days - Boulder, MT
Average visibility - Boulder, MT

Months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
Months with the lowest visibility are January, February, March and December (5mi).