Climate and Average Weather Year Round in Bozeman United States

In Bozeman, the summers are short, warm, and mostly clear and the winters are freezing, snowy, and partly cloudy. Over the course of the year, the temperature typically varies from 12°F to 84°F and is rarely below -7°F or above 93°F.

Based on the tourism score, the best time of year to visit Bozeman for warm-weather activities is from early July to mid August.

The warm season lasts for 2.8 months, from June 17 to September 10, with an average daily high temperature above 73°F. The hottest month of the year in Bozeman is July, with an average high of 83°F and low of 50°F.

The cold season lasts for 3.4 months, from November 16 to February 29, with an average daily high temperature below 40°F. The coldest month of the year in Bozeman is December, with an average low of 14°F and high of 31°F.

In Bozeman, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Bozeman begins around June 12 and lasts for 4.0 months, ending around October 12.

The clearest month of the year in Bozeman is July, during which on average the sky is clear, mostly clear, or partly cloudy 75% of the time.

The cloudier part of the year begins around October 12 and lasts for 8.0 months, ending around June 12.

The cloudiest month of the year in Bozeman is March, during which on average the sky is overcast or mostly cloudy 62% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Bozeman varies throughout the year.

The wetter season lasts 2.7 months, from April 6 to June 27, with a greater than 25% chance of a given day being a wet day. The month with the most wet days in Bozeman is May, with an average of 10.9 days with at least 0.04 inches of precipitation.

The drier season lasts 9.3 months, from June 27 to April 6. The month with the fewest wet days in Bozeman is January, with an average of 4.0 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Bozeman changes throughout the year.

Rain alone is the most common for 9.0 months, from February 25 to November 26. The month with the most days of rain alone in Bozeman is May, with an average of 10.2 days.

Snow alone is the most common for 2.9 months, from November 26 to February 23. The month with the most days of snow alone in Bozeman is December, with an average of 2.5 days.

Mixed snow and rain is the most common for 2.0 days, from February 23 to February 25. The month with the most days of mixed snow and rain in Bozeman is March, with an average of 1.9 days.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Bozeman experiences significant seasonal variation in monthly rainfall.

The rainy period of the year lasts for 8.0 months, from March 13 to November 14, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Bozeman is May, with an average rainfall of 2.3 inches.

The rainless period of the year lasts for 4.0 months, from November 14 to March 13. The month with the least rain in Bozeman is January, with an average rainfall of 0.2 inches.

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Bozeman experiences significant seasonal variation in monthly snowfall.

The snowy period of the year lasts for 6.8 months, from October 16 to May 10, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Bozeman is December, with an average snowfall of 4.1 inches.

The snowless period of the year lasts for 5.2 months, from May 10 to October 16. The least snow falls around July 27, with an average total accumulation of 0.0 inches.

The length of the day in Bozeman varies significantly over the course of the year. In 2024, the shortest day is December 21, with 8 hours, 41 minutes of daylight; the longest day is June 20, with 15 hours, 43 minutes of daylight.

The earliest sunrise is at 5:34 AM on June 15, and the latest sunrise is 2 hours, 32 minutes later at 8:06 AM on November 2. The earliest sunset is at 4:39 PM on December 10, and the latest sunset is 4 hours, 38 minutes later at 9:17 PM on June 25.

Daylight saving time (DST) is observed in Bozeman during 2024, starting in the spring on March 10, lasting 7.8 months, and ending in the fall on November 3.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The perceived humidity level in Bozeman, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Bozeman experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 5.9 months, from October 20 to April 15, with average wind speeds of more than 7.0 miles per hour. The windiest month of the year in Bozeman is January, with an average hourly wind speed of 8.7 miles per hour.

The calmer time of year lasts for 6.1 months, from April 15 to October 20. The calmest month of the year in Bozeman is August, with an average hourly wind speed of 5.3 miles per hour.

The predominant average hourly wind direction in Bozeman varies throughout the year.

The wind is most often from the west for 7.7 months, from March 13 to November 3, with a peak percentage of 48% on October 22. The wind is most often from the south for 4.3 months, from November 3 to March 13, with a peak percentage of 56% on January 1.

To characterize how pleasant the weather is in Bozeman throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Bozeman for general outdoor tourist activities is from early July to mid August, with a peak score in the last week of July.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Bozeman for hot-weather activities is from mid July to mid August, with a peak score in the last week of July.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Bozeman typically lasts for 3.7 months (113 days), from around May 25 to around September 15, rarely starting before May 6 or after June 15, and rarely ending before August 29 or after October 2.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Bozeman should appear around May 4, only rarely appearing before April 21 or after May 20.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.0 months, from May 19 to August 20, with an average daily incident shortwave energy per square meter above 6.5 kWh. The brightest month of the year in Bozeman is July, with an average of 7.6 kWh.

The darker period of the year lasts for 3.5 months, from October 28 to February 12, with an average daily incident shortwave energy per square meter below 2.8 kWh. The darkest month of the year in Bozeman is December, with an average of 1.6 kWh.

For the purposes of this report, the geographical coordinates of Bozeman are 45.680 deg latitude, -111.039 deg longitude, and 4,813 ft elevation.

The topography within 2 miles of Bozeman contains significant variations in elevation, with a maximum elevation change of 561 feet and an average elevation above sea level of 4,845 feet. Within 10 miles contains significant variations in elevation (4,728 feet). Within 50 miles also contains extreme variations in elevation (7,388 feet).

The area within 2 miles of Bozeman is covered by artificial surfaces (48%), grassland (19%), cropland (17%), and shrubs (15%), within 10 miles by cropland (30%) and trees (28%), and within 50 miles by grassland (35%) and trees (32%).