Expand
Contents
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Weather in January
January, like December, is another subzero cold winter month in Boulder, Montana, with an average temperature varying between 29.7°F (-1.3°C) and 14.5°F (-9.7°C). January notes an average high-temperature of a still subzero cold 29.7°F (-1.3°C), subtly differing from December's 27°F (-2.8°C). Weather in January »
Weather in February
February, the last month of the winter in Boulder, is also a subzero cold month, with an average temperature varying between 13.5°F (-10.3°C) and 29.3°F (-1.5°C). Boulder experiences an average high-temperature of a still freezing cold 29.3°F (-1.5°C) with the onset of February, subtly varied from January's 29.7°F (-1.3°C). Weather in February »
Weather in March
March, the first month of the spring in Boulder, is a wintry month, with an average temperature ranging between max 38.7°F (3.7°C) and min 21.6°F (-5.8°C). Boulder's March weather shows an increase in high-temperatures, moving from February's freezing cold 29.3°F (-1.5°C) to a wintry 38.7°F (3.7°C). Weather in March »
Weather in April
April is a frosty spring month in Boulder, Montana, with an average temperature varying between 27°F (-2.8°C) and 46.4°F (8°C). April's arrival coincides with a marginal rise in the average high-temperature, moving from March's icy 38.7°F (3.7°C) to a chilly 46.4°F (8°C). Weather in April »
Weather in May
May, the last month of the spring in Boulder, is a moderate month, with an average temperature ranging between min 35.2°F (1.8°C) and max 58.5°F (14.7°C). The arrival of May brings a temperature shift, with the average high-temperature escalating from a chilly 46.4°F (8°C) in April to a refreshing 58.5°F (14.7°C). Weather in May »
Weather in June
June, the first month of the summer in Boulder, is a pleasant month, with an average temperature ranging between max 68.5°F (20.3°C) and min 42.4°F (5.8°C). Boulder's June weather shows an increase in high-temperatures, moving from May's moderate 58.5°F (14.7°C) to an agreeable 68.5°F (20.3°C). Weather in June »
Weather in July
July is a moderately hot summer month in Boulder, Montana, with an average temperature fluctuating between 79.7°F (26.5°C) and 48.4°F (9.1°C). In Boulder, the average temperatures in July are the highest, with a peak at 79.7°F (26.5°C) and a low of 48.4°F (9.1°C). Weather in July »
Weather in August
The last month of the summer, August, is another warm month in Boulder, Montana, with an average temperature fluctuating between 48.6°F (9.2°C) and 77.5°F (25.3°C). As Boulder, Montana, steps into August, the average high-temperature holds at a still moderately hot 77.5°F (25.3°C), hinting at a minor fluctuation from the prior month. Weather in August »
Weather in September
September, the first month of the autumn in Boulder, is also an enjoyable month, with temperature in the range of an average high of 67.5°F (19.7°C) and an average low of 42.4°F (5.8°C). Start of September brings a shift in the average high-temperature, falling from August's warm 77.5°F (25.3°C) to a refreshing 67.5°F (19.7°C). Weather in September »
Weather in October
October, like September, in Boulder, Montana, is a cool autumn month, with an average temperature varying between 50.9°F (10.5°C) and 31.3°F (-0.4°C). Boulder's transition into October is marked by a clear drop in the average high-temperature, receding from a comfortable 67.5°F (19.7°C) in September to a fresh 50.9°F (10.5°C). Weather in October »
Weather in November
The last month of the autumn, November, is another cold month in Boulder, Montana, with an average temperature varying between 21.2°F (-6°C) and 36.9°F (2.7°C). As October transitions to November, the average high-temperature falls from a fresh 50.9°F (10.5°C) to a cold 36.9°F (2.7°C). Weather in November »
Weather in December
The first month of the winter, December, is also a subzero cold month in Boulder, Montana, with an average temperature fluctuating between 27°F (-2.8°C) and 12.6°F (-10.8°C). Boulder experiences its lowest temperatures in December, with an average peak of 27°F (-2.8°C) and a low of 12.6°F (-10.8°C). Weather in December »
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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 much does it rain in Boulder?
Throughout the year, there are 133.7 rainfall days, and 16.38" (416mm) of precipitation is accumulated.
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?
Throughout the year, in Boulder, Montana, there are 105.8 snowfall days, and 55.12" (1400mm) of snow is accumulated.
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.
What is the snowiest month in Boulder?
The month with the most snowfall in Boulder 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?
With an average maximum UV index of 1, February is the month with the lowest UV index.
When is Daylight Saving Time (DST) in Boulder?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Boulder, and the time zone changes from MST to MDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from MDT to MST.
What is the wettest month in Boulder?
The month with the most rainfall is June, when the rain falls for 16 days and typically aggregates up to 2.68" (68mm) of precipitation.
When are the longest days in Boulder?
With an average of 15h and 42min of daylight, June has the longest days of the year in Boulder.
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.
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?
With an average of 11.7h of sunshine, July has the most sunshine of the year in Boulder.
What is the month with the highest UV index in Boulder?
The month with the highest UV index in Boulder, Montana, is July, with an average maximum UV index of 6.
What is the least humid month in Boulder?
The least humid month in Boulder, Montana, is August, with an average relative humidity of 46%.
What are the coldest months in Boulder?
Boulder records the coldest temperatures in December, averaging a high of 27°F (-2.8°C) and a low of 12.6°F (-10.8°C).
What is the driest month in Boulder?
December is the month with the least rainfall. Rain falls for 8.2 days and accumulates 0.79" (20mm) of precipitation.
What is the month with the shortest days in Boulder?
The month with the shortest days in Boulder, Montana, is December, with an average of 8h and 42min of daylight.
Average temperature
Boulder, MT
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is December (27°F).
The month with the highest average low temperature is August (48.6°F).
The coldest month (with the lowest average low temperature) is December (12.6°F).
Average pressure
Boulder, MT
- Average pressure in January:
30.19"Hg - Average pressure in February:
30.13"Hg - Average pressure in March:
30.04"Hg - Average pressure in April:
29.98"Hg - Average pressure in May:
29.95"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
29.98"Hg - Average pressure in October:
30.05"Hg - Average pressure in November:
30.11"Hg - Average pressure in December:
30.18"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Boulder, MT
- Average wind speed in January:
6.5mph - Average wind speed in February:
6.2mph - Average wind speed in March:
6.2mph - Average wind speed in April:
6.4mph - Average wind speed in May:
5.4mph - Average wind speed in June:
5.6mph
- Average wind speed in July:
4.9mph - Average wind speed in August:
4.7mph - Average wind speed in September:
5.4mph - Average wind speed in October:
6.2mph - Average wind speed in November:
6.5mph - Average wind speed in December:
6.4mph
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 humidity
Boulder, MT
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is August (46%).
Average rainfall
Boulder, MT
- Average rainfall in January:
0.83" - Average rainfall in February:
1.22" - Average rainfall in March:
1.46" - Average rainfall in April:
2.01" - Average rainfall in May:
2.36" - Average rainfall in June:
2.68"
- Average rainfall in July:
1.02" - Average rainfall in August:
0.91" - Average rainfall in September:
1.14" - Average rainfall in October:
1.06" - Average rainfall in November:
0.91" - Average rainfall in December:
0.79"
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 rainfall days in January:
7.9 days - Average rainfall days in February:
8.7 days - Average rainfall days in March:
11.9 days - Average rainfall days in April:
14.8 days - Average rainfall days in May:
18.2 days - Average rainfall days in June:
16 days
- Average rainfall days in July:
9.9 days - Average rainfall days in August:
9.8 days - Average rainfall days in September:
9.8 days - Average rainfall days in October:
11 days - Average rainfall days in November:
7.5 days - Average rainfall days in December:
8.2 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is November (7.5 days).
Average snowfall
Boulder, MT
- Average snowfall in January:
6.57" - Average snowfall in February:
9.72" - Average snowfall in March:
9.53" - Average snowfall in April:
7.8" - Average snowfall in May:
2.64" - Average snowfall in June:
0.31"
The month with the highest snowfall is February (9.72").
The months with the least snowfall are July and August (0").
Average snowfall days
Boulder, MT
- Average snowfall days in January:
16.3 days - Average snowfall days in February:
18 days - Average snowfall days in March:
16.9 days - Average snowfall days in April:
12.3 days - Average snowfall days in May:
4.4 days - Average snowfall days in June:
0.9 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
1.2 days - Average snowfall days in October:
6.5 days - Average snowfall days in November:
12.5 days - Average snowfall days in December:
16.8 days
The month with the highest number of snowfall days is February (18 days).
The months with the least snowfall days are July and August (0 days).
Average daylight / Average sunshine
Boulder, MT
- Average daylight in January:
9h and 1min - Average daylight in February:
10h and 2min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 4min - Average daylight in May:
15h and 0min - Average daylight in June:
15h and 4min
- Average daylight in July:
15h and 2min - Average daylight in August:
14h and 1min - Average daylight in September:
12h and 3min - Average daylight in October:
10h and 5min - Average daylight in November:
9h and 2min - Average daylight in December:
8h and 4min
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:
5h and 4min - Average sunshine in February:
6h and 1min - Average sunshine in March:
7h and 4min - Average sunshine in April:
9h and 1min - Average sunshine in May:
10h and 1min - Average sunshine in June:
11h and 1min
- Average sunshine in July:
11h and 4min - Average sunshine in August:
11h and 3min - Average sunshine in September:
9h and 5min - Average sunshine in October:
7h and 0min - Average sunshine in November:
6h and 1min - Average sunshine in December:
5h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The months with the least sunshine are January and December (Average sunshine: 5h and 36min).
Average sunshine days
Boulder, MT
- Average sunshine days in January:
14.3 days - Average sunshine days in February:
8.5 days - Average sunshine days in March:
9.2 days - Average sunshine days in April:
8.9 days - Average sunshine days in May:
9.3 days - Average sunshine days in June:
10.7 days
- Average sunshine days in July:
17 days - Average sunshine days in August:
17 days - Average sunshine days in September:
17.9 days - Average sunshine days in October:
15 days - Average sunshine days in November:
14.9 days - Average sunshine days in December:
13.7 days
The month with the most sunshine days is September (17.9 days).
The month with the least sunshine days is February (8.5 days).
Average UV index
Boulder, MT
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover
Boulder, MT
The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 15).
Average visibility
Boulder, MT
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).
Boulder, Montana, USA
Weather forecast for your location
1. Click Locate me button
2. Allow the app to use your location
2. Allow the app to use your location