Deconstruct SunMontana Hardiness Zones
Montana covers USDA plant hardiness zones 3b to 6b on the 2023 map, so its coldest areas average −35 to −30 °F on the coldest winter night. Find your zone by ZIP code, or pick a city below for its zone, sunrise and daylight by month.
Montana hardiness zone map
This is not the official USDA Plant Hardiness Zone Map. Zones are derived from the official 2023 dataset, resampled to about 2 km. Dots mark cities with their own page.
Source: USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture, planthardiness.ars.usda.gov. Underlying data © PRISM Group, Oregon State University, prism.oregonstate.edu, accessed 2026-08-30.
Zones and daylight by city
| City | Zone | Coldest night | Longest day | Shortest day |
|---|---|---|---|---|
| Billings | 5a | −20 to −15 °F | 15h 44m | 8h 40m |
| Missoula | 5b | −15 to −10 °F | 15h 53m | 8h 32m |
| Great Falls | 4b | −25 to −20 °F | 15h 58m | 8h 26m |
| Bozeman | 5a | −20 to −15 °F | 15h 43m | 8h 41m |
| Helena | 5a | −20 to −15 °F | 15h 50m | 8h 34m |
| Butte | 4a | −30 to −25 °F | 15h 45m | 8h 38m |
| Kalispell | 5b | −15 to −10 °F | 16h 05m | 8h 20m |
Gardening in Montana?
Your zone says what survives winter. Deconstruct Sun measures how many hours of direct sun your exact spot gets, so you can pick plants that thrive. Free on iPhone.
Questions
What hardiness zones are in Montana?
Montana spans USDA zones 3b to 6b on the 2023 map. Among its larger cities, Butte is coldest (zone 4a) and Missoula is warmest (zone 5b).
How do I find my exact zone in Montana?
Enter your ZIP code in the hardiness zone lookup on this site. It reads the 2023 USDA data for that ZIP and warns you if you are near a zone boundary.
How much sun do gardens in Montana get?
In Billings, an open spot gets up to 15.7 hours of daylight in June but only 8.7 in December. Trees and buildings cut that down, especially in winter. The Deconstruct Sun app measures the real direct-sun hours for one exact spot.