Boise, Idaho – After several mild and mostly sunny days, a strong fall cold front will sweep through southwest Idaho late this weekend, bringing valley rain and heavy mountain snow from Sunday into Monday. The change will mark the region’s first significant taste of winter-like weather this season.
According to the National Weather Service office in Boise, temperatures will stay pleasant through Friday, with highs near 65°F in Boise and upper 50s in McCall. Clouds will increase Saturday ahead of the front, followed by widespread rain developing Sunday. Mountain passes and ski areas, including Brundage, Tamarack, and Sun Valley, are forecast to receive 6–12 inches of snow by late Monday, with the heaviest totals over Banner Summit and Brundage Mountain.
Rainfall in the Treasure Valley could total up to a half inch, making for slick roads and reduced visibility during Sunday travel. Temperatures will plunge behind the front, with Monday highs only in the 40s for the valleys and 30s in the higher terrain. Gusty northwest winds will add to the chill as snow levels drop below 5,000 feet.
Forecasters urge hunters, hikers, and motorists heading into the mountains to prepare for winter driving conditions, especially Sunday night into early Monday. Drier, calmer weather is expected to return by Tuesday as high pressure rebuilds.
Five-Day Forecast for Boise, ID:
Wed: 63/39 – Sunny; mild fall day.
Thu: 64/40 – Clear and pleasant.
Fri: 68/42 – Mostly sunny; warmest day of week.
Sat: 59/39 – Increasing clouds; cooler late.
Sun: 54/35 – Rain develops; mountain snow by night.
