Halloween in Montana usually signals the change from crisp fall days to those first hints of winter. Chilly evenings are the norm, and in plenty of towns, snow starts to feel possible by late October.
Most years, you’ll want to prep for cold temperatures and maybe some light rain or snow around Halloween in Montana.
Your exact Halloween weather really depends on where you are. In Billings, late October brings cool but manageable days, while Bozeman and Missoula often get colder nights and a bigger chance of early snow.
These differences make it a little tougher to plan costumes and outdoor fun—especially if you want to stay comfortable.
Knowing what’s likely helps you plan for both the festivities and the weather. Whether you’re wandering a corn maze, trick-or-treating, or joining a fall festival, understanding Montana’s late October climate can help you avoid surprises.
Typical Halloween Weather in Montana
When you’re planning for Halloween in Montana, expect chilly evenings, a chance of precipitation, and shorter daylight hours.
The state’s geography creates a lot of variation, so your experience can change a lot depending on whether you’re in the mountains, valleys, or out on the eastern plains.
Average Temperatures on Halloween
Temperatures on Halloween in Montana usually land in the 40s during the day and drop into the 20s or 30s at night. In the western valleys, highs tend to stick around the mid-40s.
Out east, afternoons can be a bit warmer, sometimes reaching the upper 40s or low 50s.
Once the sun sets, temps fall fast. Lows in the 20s are standard across the east, while central and western spots often see upper 20s or low 30s.
If you’re up in the mountains, nighttime readings can even dip into the teens.
Wind chill can make a big difference. Even a light breeze can make trick-or-treating feel colder than what the thermometer says. Layering under costumes is still the best way to stay warm.
| Region | Typical High (°F) | Typical Low (°F) |
|---|---|---|
| Western Valleys | 43–47 | 28–32 |
| Central Montana | 40–45 | 25–30 |
| Eastern Plains | 47–52 | 22–28 |
| Mountain Areas | 35–40 | 15–25 |
Precipitation Patterns and Chances
Halloween in Montana can swing between dry and wet years. Billings usually records about 0.09 inches of precipitation for October 31, but some years barely see a drop.
Light rain or snow showers aren’t rare, especially in the west.
Western Montana tends to get more moisture. Cold fronts roll through and can bring a rain-snow mix to places like Missoula or West Yellowstone.
Eastern Montana is drier overall, but even there, a quick system can drop flurries or drizzle.
Snowfall is possible but usually light. You’ll see more accumulating snow in higher elevations, while valley towns might just get a brief shower. If you’re traveling between communities, slick roads can pop up fast.
Cloud Cover and Daylight Hours
By late October, Montana days feel short. Sunset usually falls around 6 p.m. to 6:30 p.m., so trick-or-treating often happens in the dark.
Less daylight means it cools off fast once the sun’s down.
Cloud cover really varies. Some Halloweens have clear skies, while others are just plain overcast.
Thin clouds can trap a bit of warmth, but thick cover usually means unsettled weather.
Eastern Montana often gets clearer skies, but in the western valleys, clouds and fog show up more because of the mountains. If fog rolls in after sunset, visibility can drop fast in some areas.
Clear nights tend to feel colder since heat escapes quickly, while cloudy nights might stay a little milder but damp. Both patterns are totally normal for late October in Montana.
Regional Halloween Weather Differences
Montana’s weather at the end of October changes fast depending on your location. Mountain valleys usually bring colder, wetter conditions, while the plains stay drier but still chilly.
These differences matter when you’re planning outdoor activities or prepping for trick-or-treating.
Western Montana: Missoula and Surroundings
In western Montana, including Missoula, you’ll usually deal with colder and wetter Halloweens. The mountains trap moisture, so rain and snow showers happen often.
A cold front can bring a wintry mix, especially in the valleys, where highs stick to the 40s and nighttime lows fall below freezing.
Snow is more likely up in the Bitterroot or Centennial Mountains. Some years, several inches pile up in the passes, making travel tough.
Even in Missoula, light snow or cold rain can show up by evening.
Clouds hang around a lot, keeping things damp and chilly. You’ll want to bundle up in layers, maybe even waterproof gear.
After dark, icy sidewalks and slushy side streets can be a hassle for families.
Typical conditions:
- Daytime highs: 40s °F
- Nighttime lows: 20s–30s °F
- Precipitation: Rain/snow mix, especially in valleys
Eastern Montana: Billings and Prairie Areas
Eastern Montana, including Billings, usually has drier conditions but still sees sharp temperature drops. Average precipitation on Halloween is low, often less than a tenth of an inch, so rain or snow isn’t as common as it is out west.
Daytime highs can reach the low 50s, but evenings drop into the 30s or 40s. Winds across the prairie add to the chill, so it can feel colder than the numbers suggest.
Skies are more likely to clear after sunset compared to the western valleys.
Snow happens, but not as often and usually not much. More often, you’ll deal with crisp, dry air and gusty breezes.
Costumes are easier to manage here since you don’t usually need heavy, wet layers like in Missoula.
Typical conditions:
- Daytime highs: 50s °F
- Nighttime lows: 30s–40s °F
- Precipitation: Light and infrequent
Temperature Trends in Late October
Late October in Montana really feels like the shift from fall to early winter. Afternoons get cooler, mornings are chilly, and snow becomes a real possibility, especially in the mountains.
Conditions can swing quite a bit by elevation, but the big trend is a steady drop in both daytime and nighttime temps.
Daytime Highs and Lows
By the last week of October, daytime highs usually land in the upper 40s to low 50s °F (8–12 °C) in most lower-elevation towns.
Up in the mountain valleys, highs may only make it to the low 40s °F (4–6 °C).
Afternoon warmth doesn’t last long, and with the sun setting earlier, temperatures cool off quickly. Some days, places like Billings might still hit 55–60 °F (13–16 °C), but that’s less common after mid-month.
Lows during the day often sit in the mid-30s °F (1–3 °C). Frost on the ground is a regular sight, and some regions may get a light snow shower. Layering is key for any outdoor plans.
Typical late October daytime range:
| Location | Highs (°F) | Lows (°F) |
|---|---|---|
| Billings (low elevation) | 50–60 | 33–38 |
| Missoula (valley) | 48–55 | 32–36 |
| Whitefish (mountain town) | 42–48 | 30–34 |
Nighttime and Early Morning Conditions
Nights in late October are cold, with temps dropping into the upper 20s to low 30s °F (-2 to 2 °C). In the mountain valleys, you might see mid-20s °F (-4 °C).
Frost is almost a given most mornings, and icy patches can form on roads and sidewalks.
Early mornings are the coldest. Dense valley fog can show up, especially near rivers and lakes, making driving tricky.
If a cold front moves through, you might even wake up to a dusting of snow at higher elevations.
Wind chill really bites in open areas. A 35 °F (2 °C) morning with a steady breeze can feel more like the mid-20s °F (-4 to -6 °C).
Wearing layers, gloves, and a hat helps keep you comfortable for early outings.
Longer nights mean temps stay low for more hours, so homes and cabins cool off quickly without steady heat. If you’re camping or spending the night outdoors, bring gear that’s ready for freezing conditions.
Precipitation and Snowfall Expectations
Late October in Montana usually brings unsettled weather. Cooler temperatures mix with rain and snow, depending on where you are and your elevation.
Precipitation is pretty common, and the type can switch fast, sometimes even during the same day.
Rainfall Averages
Rainfall around Halloween is usually light to moderate, but it depends on the city. In lower elevations like Billings, late October averages about 0.3 to 0.5 inches.
That’s enough for damp streets and the occasional puddle, but rarely causes big problems.
The number of wet days goes up in late October. Many Montana areas average 10 to 12 days of measurable precipitation during the month.
By Halloween, the chance of rain on any given day is about 25–30%.
Rain usually comes as short showers instead of long storms. If you’re planning to be outside, expect cool, damp weather and keep rain gear handy.
Evening temps can turn rain into snow, especially after sunset.
Snowfall Possibilities
Snow gets more likely as October wraps up, especially in central and western Montana.
Cities like Bozeman and Missoula often see their first measurable snowfalls by late October.
Average snowfall for the month runs from 1 to 3 inches in the valleys, but mountain areas can get much more.
The odds of snow on Halloween itself aren’t huge everywhere, but it’s not rare either.
Some years, there’s no snow at all, while others bring several inches. Billings, for example, has had both dry Halloweens and ones with snow on the ground.
If snow shows up, roads can get slick and evenings feel colder. Even a light dusting can make things icy after dark, especially if daytime rain refreezes.
Anyone traveling or trick-or-treating should prep for changing conditions.
Weather Considerations for Halloween Activities
Late October in Montana often means chilly evenings, dry air, and a chance for light snow or rain.
You’ll want to prep for colder-than-average temps, especially after sunset, and make sure your plans fit the conditions.
Trick-or-Treating Tips
Temperatures on Halloween night in Montana usually drop into the 20s and 30s. Wind can make it feel even colder, so you’ll want to be ready for a brisk walk from house to house.
Streets can get slick if there’s frost or a touch of snow.
Plan your route ahead of time. Look for neighborhoods with good lighting and sidewalks.
Rural areas can have uneven ground or darker roads, which get tricky in cold weather.
Since it gets dark early, start trick-or-treating soon after sunset. That way, you avoid the coldest hours.
Carrying a flashlight or wearing something reflective makes you more visible to drivers, especially if streets are icy or dim.
Costume and Safety Recommendations
Your costume should work with the weather, not against it. Lightweight outfits alone won’t keep you warm, so try layering thermal shirts, leggings, or fleece underneath.
That way, you stay comfortable without needing a bulky coat.
Masks and hats can limit your vision, especially in the dark. Face paint is a better bet so you can see clearly.
If you do wear a hat or hood, make sure it doesn’t block your side view.
Add some reflective tape or glow sticks to costumes and bags. Drivers may have a hard time seeing you in the dark, especially if roads are damp or icy.
Good footwear matters too—pick shoes with some traction instead of thin or slick soles.
Comparing Halloween Weather to Other Times of Year
Halloween in Montana usually lands right as the seasons are shifting. You’ll notice cooler temperatures than you had in early fall, but honestly, the real winter cold hasn’t kicked in yet. Precipitation can happen, but snow? That’s still not as common as it will be in the coming months.
How Halloween Compares to Early Fall
September afternoons generally feel warmer. In Billings, average highs hit about 76°F. Missoula and Bozeman tend to hang out in the low 70s.
By October 31, those highs usually fall into the 50s or low 60s. Halloween definitely feels chillier.
Evenings bring an even bigger change. In September, overnight lows range from the 40s to low 50s. Late October often drops into the 30s or low 40s.
So, trick-or-treating gets that crisp edge, and you’ll probably want a jacket over your costume.
Rain doesn’t show up as much as it did in September. Billings averages about 0.9 inches of rain in September, but October only sees around 0.8 inches.
Missoula and Bozeman see the same thing, with conditions getting a bit drier by Halloween.
Daylight really changes things, too. In September, you still get more than 12 hours of daylight. By late October, it shrinks to about 10.5 hours.
The sun sets earlier, so evening activities feel darker and a bit colder than they did just a month before.
Transition to Winter Weather
By November, Montana starts shifting into more winter-like conditions. Average highs in Billings drop into the 40s. Lows usually dip below freezing.
Missoula and Bozeman cool down even faster. By mid-November, their average lows sit in the 20s.
Snow shows up more often after Halloween. Since 1897, Halloween has only seen measurable snowfall a handful of times. November, though, usually brings regular snow events.
Billings picks up about 1.0 inch of snow in November. That’s double what it gets in October, which averages just 0.5 inch.
Winds pick up as winter moves in. In Billings, average wind speeds rise from about 9.2 mph in October to nearly 10 mph in November. That extra breeze definitely adds to the chill.
So, Halloween falls in a sort of in-between zone. It’s cooler than early fall, but you don’t really get the harsh winter weather just yet. Most years, you’ll run into brisk, dry evenings before snow and freezing nights really settle in.