Boat Winterization in Montana

In Montana, local boat deadlines run from Sep 26 to Oct 5, with a median around Oct 4 — a spread of weeks that a single statewide date would miss. Find your city below; each links to local freeze odds, a live 10-day outlook, and a checklist.

Covered boat locked in ice beside a dock on a frozen lake — winterize the engine before the first hard freeze catches it in the water — Montana deadlines city by city — Photo: Unsplash

Jump to a city

Notable cities

Bozeman — earliest deadline in the state
Missoula — latest deadline in the state
Great Falls — near the state median

All Montana cities

City	Local deadline	Median first 28°F
Bozeman	Sep 26	Oct 3	View →	Checklist
Helena	Sep 30	Oct 7	View →	Checklist
Great Falls	Oct 4	Oct 11	View →	Checklist
Billings	Oct 5	Oct 12	View →	Checklist
Missoula	Oct 5	Oct 12	View →	Checklist

Local boat winterization deadlines for Montana cities — built from each city’s own NOAA station, not one statewide date.

Boat Winterization in Montana: related searches

Montana homeowners search for: how to winterize a boat, winterize outboard motor, and "boat winterization near me" — every city page below answers those with local NOAA dates.

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Back to the national Boat Winterization guide, or see the methodology. You can also compare how the boat winterization window shifts in Missouri and Nebraska.

Data: NOAA NCEI 1991–2020 U.S. Climate Normals; live outlook by Open-Meteo. Last updated: July 25, 2026.