Idaho Snow Day Calculator: Chances & Closure Norms
What closes Idaho schools? Snowday's Idaho calculator typically flags a snow day at just 2–3 inches in the Treasure Valley, where Boise averages about 19 inches a year — while mountain towns like McCall (about 130 inches) plow through far more. Enter your ZIP code above for tomorrow's chance.
Snow day calculator
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Result
Your forecast appears here. Enter a ZIP code or city above and press Calculate snow day chance.
Fun estimate only — always follow your school district’s official announcements.
How Idaho districts decide snow days
In the Boise metro (West Ada, Boise, Vallivue districts), the trigger is timing: 2 to 3 inches falling directly on the 5–9 a.m. commute closes or delays schools, because valley ice under fresh snow is the region’s real hazard. Delayed starts are the standard response when the morning window looks bad but the afternoon clears.
Eastern Idaho (Idaho Falls, Pocatello) handles around 40 inches a year and closes in the 4-to-6-inch range, with wind adding to the score. Mountain districts along U.S. 95 and the Panhandle close mainly when state highways close or when freezing rain glazes the grades.
Average snowfall in Idaho
| Place | Avg. snow per year |
|---|---|
| Boise | ≈ 19 in/yr |
| Pocatello | ≈ 40 in/yr |
| McCall | ≈ 130 in/yr |
Averages are approximate NOAA/NCEI 1991–2020 climate normals, rounded; resort areas like Schweitzer and Sun Valley report 200+ inch seasons. The Boise number illustrates the inversion problem: valley cold air often means snow arrives as ice first.
The storm Idaho remembers
The January 2017 inversion winter. The 2016–17 winter dumped record snow on Boise — nearly 40 inches in December and January combined — collapsing buildings and closing schools repeatedly while valley inversions kept temperatures below freezing for weeks. For a city that averages 19 inches a season, it was a generational disruption.
Using the calculator in Idaho
Snowday balances Idaho with a 5-inch statewide baseline; Boise users should slide strictness toward “strict” to reflect the valley’s low tolerance. Open the snow day calculator and enter ZIP 83702. For the full picture, open the snow day calculator and see how commute-hour snowfall, cold, and wind combine into tomorrow’s percent chance — free, instant, no sign-up.
Last updated: October 2026