USDA hardiness zone 5a
USDA plant hardiness zone 5a covers areas whose average annual extreme minimum winter temperature is −20 to −15 °F — the standard USDA measure of which perennials survive an average winter. Hardiness zone sets winter survival, but planting DATES depend on your local frost calendar, which varies within a zone. 631 locations on this site fall in zone 5a (Absarokee, MT, Akwesasne, NY, Alba, MI, Albert Lea, MN, Alcova, WY, Algona, IA, Allen, SD, Alliance, NE, and 623 more); open one to see its frost dates, growing-season length, and a printable per-crop planting calendar.
Locations in zone 5a — 60 of 631
| Location | Last frost | First frost | Season (days) |
|---|---|---|---|
| Absarokee, MT | Jun 1 | Sep 11 | 100 |
| Alta, WY | Jun 14 | Sep 11 | 85 |
| Armstrong, IA | May 4 | Oct 1 | 150 |
| Atlantic, WY | May 13 | Oct 2 | 140 |
| Bearcreek, MT | Jun 3 | Sep 19 | 106 |
| Bethel, ME | May 30 | Sep 19 | 112 |
| Blanca, CO | May 25 | Sep 22 | 117 |
| Boscobel, WI | May 3 | Oct 7 | 155 |
| Brodhead, WI | Apr 29 | Oct 12 | 165 |
| Campbellsport, WI | May 1 | Oct 10 | 160 |
| Chain O' Lakes, WI | May 8 | Oct 6 | 151 |
| Chelsea, VT | May 9 | Oct 1 | 143 |
| Clyde Park, MT | May 27 | Sep 14 | 108 |
| Conrad, IA | Apr 30 | Oct 6 | 159 |
| Custer, SD | May 23 | Sep 24 | 122 |
| Dolgeville, NY | May 5 | Oct 4 | 151 |
| Eden, WI | May 1 | Oct 12 | 162 |
| Esterbrook, WY | Jun 2 | Sep 9 | 99 |
| Fairview, WY | Jun 20 | Sep 1 | 71 |
| Freeman, SD | May 1 | Oct 4 | 156 |
| Glens Falls North, NY | May 17 | Sep 29 | 135 |
| Greenland, MI | May 27 | Oct 1 | 127 |
| Harrisburg, NE | May 24 | Sep 20 | 117 |
| Hebgen Lake Estates, MT | Jun 15 | Sep 10 | 87 |
| Houston, MN | May 8 | Oct 3 | 147 |
| Indian River, MI | May 31 | Sep 18 | 108 |
| K. I. Sawyer, MI | May 13 | Oct 2 | 141 |
| Keystone, CO | Jun 6 | Sep 19 | 103 |
| La Crosse, WI | Apr 27 | Oct 13 | 167 |
| Le Mars, IA | Apr 30 | Oct 4 | 157 |
| Lindy, NE | Apr 30 | Oct 8 | 160 |
| Lupton, MI | May 21 | Sep 29 | 129 |
| Macy, NE | May 1 | Oct 6 | 156 |
| Maquoketa, IA | Apr 25 | Oct 14 | 171 |
| Mattawamkeag, ME | May 6 | Oct 8 | 155 |
| Midwest, WY | May 22 | Sep 22 | 121 |
| Monroe, WI | Apr 27 | Oct 14 | 170 |
| Nachusa, IL | Apr 21 | Oct 19 | 180 |
| Newberry, MI | May 21 | Oct 5 | 135 |
| Norway, MI | May 17 | Oct 1 | 135 |
| Okoboji, IA | May 1 | Oct 6 | 158 |
| Owl Creek, WY | May 5 | Oct 5 | 152 |
| Phippsburg, CO | Jun 14 | Sep 11 | 89 |
| Poland, NY | May 4 | Oct 13 | 161 |
| Prairie du Chien, WI | Apr 28 | Oct 12 | 166 |
| Redwood Falls, MN | Apr 30 | Oct 4 | 157 |
| Robertson, WY | Jun 14 | Sep 9 | 84 |
| Salem, SD | Apr 30 | Oct 7 | 161 |
| Sheffield, IA | Apr 29 | Oct 9 | 162 |
| Skowhegan, ME | May 8 | Oct 5 | 149 |
| Spencer, NE | May 4 | Oct 6 | 152 |
| Steamboat Springs, CO | Jun 9 | Sep 12 | 93 |
| Sugar, ID | May 15 | Sep 23 | 129 |
| Tipton, IA | Apr 21 | Oct 15 | 175 |
| Tyndall, SD | May 1 | Oct 7 | 158 |
| Veteran, WY | May 15 | Sep 27 | 132 |
| Walton, NY | May 21 | Oct 1 | 132 |
| Webster, IA | May 3 | Oct 2 | 150 |
| Wiggins, CO | May 6 | Oct 6 | 153 |
| Wisdom, MT | Jun 1 | Sep 17 | 107 |
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
What zone 5a means for your garden
A plant rated "hardy to zone 5a" can be expected to survive a winter whose coldest night lands in the −20 to −15 °F range — the metric the USDA map is built on. That governs perennials, shrubs, and trees. For annual vegetables, what matters is the frost calendar: the dates of the average last spring and first fall freeze, which set when it is safe to plant and how long the season runs. Those come from the individual location pages above.
Zones are from the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP — see the methodology page. Browse all hardiness zones or crop-by-crop timing.
Frequently asked questions
- What temperature range is USDA zone 5a?
- Zone 5a covers areas whose average annual extreme minimum winter temperature is −20 to −15 °F. Each numbered zone is a 10°F band; the "a" and "b" half-zones split it into 5°F steps.
- Does zone 5a tell me when to plant?
- No — the hardiness zone tells you which perennials survive winter, not when to sow annual vegetables. Planting dates depend on your local last and first frost, which can vary within a single zone. Open one of the sample locations in zone 5a to see its frost calendar and per-crop planting windows.
- What can I grow in zone 5a?
- Almost any common vegetable can be grown in zone 5a; what changes with zone and local climate is the timing and the length of the season. Cold-hardy crops (peas, spinach, lettuce) go out earliest, tender crops (tomatoes, peppers, basil) after the last frost. Use each location's calendar for exact dates.