Weather in Montana: Climate, Seasons, and Average Monthly Temperature

Montana is beautiful in summer.

Wendy Altschuler 

Montanans love to play outside, no matter the weather, and even though the winters and shoulder seasons can be quite cold and long, if you’re dressed appropriately, you’ll find that the big blue skies and wide-open spaces are worth venturing out for. The western portion of Montana is mountainous while the eastern section is prairie land. The state is split in two parts by the Continental Divide, each with its own diverse weather patterns. Temperatures also vary depending on altitude, geography, and topography. The month of July experiences peak temperatures, averaging 85 degrees-Fahrenheit and January sees the lowest temperatures, averaging 0 degrees-Fahrenheit.

Wildfire Season in Montana

Be aware that wildfires not only affect Montana’s wildlife, forests, and vast landscapes, but they can also be the cause of poor air quality and road and site closures for tourism throughout the state. Peak wildfire season occurs during the summer months when the state experiences warmer weather, lightning, and gusts of wind. A great resource to review before travel is the Montana Fire Conditions, listed on the Montana government site.

Different Regions of Montana

Northwestern Montana

The weather in northwestern Montana is unlike other areas of the state. Popular cities and towns like Kalispell, Libby, Missoula, West Glacier, and Whitefish experience an average high of 86 degrees F (30 degrees F) in July and an average high of 33 degrees F (0 degrees C) in January. Extended periods of hot weather in the summer are unlikely while freezing temperatures at night in the winter are expected. Shoulder seasons also experience frost.

The most popular destination in northwestern Montana is Glacier National Park, where the weather is much different from the rest of the region. Warm and sunny days and cool nights are the norm during the summer months, necessitating warm layers and rain gear when out exploring. The east side of the park is higher in elevation, which means that the weather is often cooler and windier. Also, the higher the elevation, the cooler the temperatures. It’s 10 to 15 degrees cooler at Logan Pass at 6,647 feet (2,026 meters) high, for example, and snow can fall at any time. The western valleys experience the most rainfall. The dryness of the east, on the other side of the Continental Divide, is due to high winds.

Southwestern Montana

In southwestern Montana, in cities like Bozeman, Butte, Helena, Virginia City, and West Yellowstone, the average high in July is 83 degrees F (28 degrees C), with an average precipitation of 1.41 inches. The average high in January is 35 degrees F (2 degrees C), with an average snowfall of 9 inches. On average, the weather during the summer is warm and dry, with mostly clear skies, and the weather in the winter is partly cloudy, snowy, and freezing. The warm-weather season is short, lasting 2.8 months on average, while the cold season lasts 3.4 months. Snow is present in this part of the state for 6.8 months on average.

Yellowstone National Park is the most visited destination in this part of the state. West Yellowstone, the gateway to the park located in Montana, enjoys sunny, dry, and warm summers and experiences biting cold winters with lots of snow from October through May. While most tourists visit during July and August, when the weather is the most cooperative and dependable, a trip to Yellowstone in the winter is quite magical. Winter months allow tourists to see the park and its animals without crowds. Adventurers can ride snowmobiles through the park and enjoy less expensive accommodations.

South Central Montana

Billings, Cooke City, and Red Lodge are popular cities in south central Montana. Billings, the state’s most populous city with a population of 110,000 people, sees an average high of 87 degrees F (30.5 degrees C) in July and an average high of 36 degrees-F (2 degrees C) in January. On average, the month of March experiences the most snowfall at 10 inches and May experiences the most rainfall at 2.18 inches. Billings has an average snowfall of 46 inches per year and the city enjoys 205 sunny days per year. Billings, and south central Montana in general, is one of the warmest areas of Montana with 151.5 days of freezing nighttime temperatures each year.

Eastern Montana

Montana is the sixth coldest state in the nation and the eastern section of big sky country sees the chilliest winter temps. Glendive, Great Falls, Havre City, Lewis Town, and Miles City are located east of the Continental Divide and experience a semi-arid steppe climate. Summer thunderstorms and snow (which can fall at any time of year) are the main sources of precipitation, which is relatively low at 10 to 20 inches per year. From June to September, the average high is 76 degrees F (24 degrees C). From November to March, the average high is below 45 degrees F (7 degrees C) with an average low of 2 degrees F (-17 degrees C).

Summer in Montana

The best time to visit Montana is typically in the summer months between June and September when the weather is warm, and the skies are sunny. Early summer is prone to rain and thunderstorms, however, so plan accordingly. Summers can be dry and hot, which increases the frequency of wildfires in the state’s forests. This season also welcomes the most tourists, especially in Glacier and Yellowstone National Parks. You should expect 14 to 16 hours of daylight during the summer months.

What to Pack: No matter what time of year, you’ll want to pack layers to make the most of your time spent in the outdoors. If you’re visiting Montana in the early summer, be sure to bring rain gear and water-resistant footwear. Extra warm layers are recommended, especially at night. Prepare for the sun by packing sunblock, hats, and long sleeves in mid-summer. If you’re visiting the mountains, be sure to drink lots of water and stay hydrated.

Spring in Montana

It can still be quite cold in spring and rainstorms are probable. Wildfires and thunderstorms are likely in late spring and early summer. With fewer crowds in the touristy areas, compared to the summer months, spring is one of the best seasons to visit the state. There are 13 to 15 hours of daylight during this season on average.

What to Pack: Rain gear—jackets, ponchos, umbrellas—is necessary as are warm layers, water-resistant boots, and sun protection. Wildflowers and plants come into view this season, as does wildlife, so be sure to prepare for any seasonal allergies and pack bear spray if you plan on hiking in the forests or mountains where bears are present.

Winter in Montana

The winter season can feel quite cold and long. Snow and wind storms happen regularly and blizzards dump many inches of snow, which can cause road, trail, and mountain pass closures for multiple days. January is the coldest, snowiest, and iciest month of the year across the state. While the winter months are the slowest in terms of tourism, outdoor adventures abound, from dog sledding to skiing to sleigh rides to ice fishing. Expect approximately 8 to 10 hours of daylight during this season.

What to Pack: Warm, thick, moisture-wicking layers are a must for visiting Montana during the winter. You’ll want to pack winter boots, wool socks, gloves, hats, snow pants, and a heavy jacket. Hand and foot warmers are also a good idea.

Fall in Montana

Expect cooler and windier conditions in autumn, especially at higher elevations. Average highs are around 60 degrees F (15.5 degrees C), however, nighttime temperatures can be quite cold at 35 degrees F (2 degrees C) on average. Visitors love seeing the fall colors spread across the state during this time and hiking, biking, kayaking, fishing, and even camping are all popular activities. Expect 10 to 13 hours of daylight during the autumn.

What to Pack: Bears are still roaming around during the fall season, so be sure to bring bear spray with you if you’ll be exploring remote areas. Night temperatures can be quite cold so pack thick and warm layers. Bring appropriate footwear as well to keep your feet dry and warm.

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