Rain, Snow or Sunshine? What Halloween Weather Looks Like Across Idaho

Ask any Idaho parent and they’ll tell you that the scariest part of Halloween isn’t haunted houses. It’s having to convince your kid to layer up under their costume or wear a jacket over it while trick-or-treating.

Almost every year you find yourself saying “you’ll freeze” and they’ll fight back “it ruins my costume!” As much as you want to be right because you’re the adult in this situation, you haven’t forgiven your parents for making you wear a puffy white sweater under your Belle costume when you were four.

Halloween is creeping up on us and by now, you’re peeking at long-range forecasts to see just how much of a battle you’re going to have this year.

The Old Farmer’s Almanac Halloween Weather Forecast for Idaho

The Old Farmer’s Almanac has been predicting the weather since 1792 and although their methods differ significantly from a traditional meteorologist’s, they claim to have an 80% accuracy rate. They’ve published a 60-day Extended Weather Forecast for dozens of Idaho cities, which covers October 31.

READ MORE: 50 Boise Area Trunk or Treats You Can't Miss in 2025

According to the Almanac, cities from the Treasure Valley and Magic Valleys to North and East Idaho will all experience the same type of weather. The prediction is “a few showers north, sunny south; turning very warm.”

That didn’t seem like enough information to help parents plan accordingly, so we found a second source and checked the long-range forecast from AccuWeather for Boise and some of Idaho’s largest cities.

What History Tells Us About Halloween Weather in Boise

Records on file with the National Weather Service show that, yes, it can and has snowed in Boise on Halloween. Based on their almost 150 years of records, the probability of snow on October 31 in any given year is just 7%. The most snow Boise’s received on Halloween was an inch in 1971. The most recent Halloween snow recorded was just a trace in 2003.

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However, the probability of it being wet on Halloween is much higher at 23% and it looks like that might be what Boise kids are up against this year.

AccuWeather’s Forecast Outlook for Halloween in Boise 2025

Right now, AccuWeather is predicting a high of 55º and low of 38º in Boise on Halloween, with temperatures right around 43º as the kids head out from trick-or-treating. Those temperatures come with a 55% probability of precipitation in the evening so it may not be a bad idea to bring along a rain jacket or poncho.

AccuWeather's Halloween Outlook for Other Major Idaho Cities

Idaho Falls

• High: 48º
• Low: 27º
• Trick-or-Treat Forecast: Morning snow and rain possible, but the evening looks drier with just a 25% chance of precipitation. Temps around 33º.

Pocatello

• High: 50º
• Low: 35º
• Trick-or-Treat Forecast: Cloudy with rain or snow early, drying out by evening. Temps near 39º and a 25% chance of rain.

Coeur d’Alene

• High: 50º
• Low: 40º
• Trick-or-Treat Forecast: Expect rain during the day that could linger into the evening. Temps around 43º with a 55% chance of rain.

Twin Falls

• High: 51º
• Low: 31º
• Trick-or-Treat Forecast: Rainy start giving way to clearer skies later. Temps around 35º, but it’ll feel closer to 29º. Bundle up!

Post Falls

• High: 49º
• Low: 40º
• Trick-or-Treat Forecast: Possible rain early in the day, with a 55% chance it continues into trick-or-treat hours. Temps near 42º.

Rexburg

• High: 47º
• Low: 30º
• Trick-or-Treat Forecast: Snow and rain possible early, but it should be mostly dry for trick-or-treating. Temps around 35º with a 25% chance of precipitation.

Lewiston

• High: 60º
• Low: 42º
• Trick-or-Treat Forecast: Showers and clouds likely throughout the day, with rain possibly lingering into the evening. Temps near 48º and a 62% chance of precipitation.

Moscow

• High: 52º
• Low: 36º
• Trick-or-Treat Forecast: Expect a damp evening with a 55% chance of rain and temperatures around 40º.

Of course, Idahoans know that if you don’t like the weather, wait five minutes—it’ll change. We’ll have to see what happens!