Deconstruct SunIdaho Hardiness Zones
Idaho covers USDA plant hardiness zones 4a to 7b on the 2023 map, so its coldest areas average −30 to −25 °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.
Idaho 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 |
|---|---|---|---|---|
| Boise | 7a | 0 to 5 °F | 15h 26m | 8h 56m |
| Meridian | 7a | 0 to 5 °F | 15h 26m | 8h 56m |
| Nampa | 7a | 0 to 5 °F | 15h 26m | 8h 56m |
| Idaho Falls | 5b | −15 to −10 °F | 15h 25m | 8h 57m |
| Pocatello | 6a | −10 to −5 °F | 15h 21m | 9h 01m |
| Coeur d'Alene | 7a | 0 to 5 °F | 16h 00m | 8h 25m |
| Twin Falls | 6b | −5 to 0 °F | 15h 19m | 9h 03m |
Gardening in Idaho?
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 Idaho?
Idaho spans USDA zones 4a to 7b on the 2023 map. Among its larger cities, Idaho Falls is coldest (zone 5b) and Boise is warmest (zone 7a).
How do I find my exact zone in Idaho?
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 Idaho get?
In Boise, an open spot gets up to 15.4 hours of daylight in June but only 8.9 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.