Zone 2a
In USDA zone 2a the coldest night of an average winter reaches −50 to −45 °F (−45.6 to −42.8 °C). 27 ZIP codes (0.1% of all) are in this zone.
Frost dates vary within zone 2a
For the middle half of zone-2a ZIP codes the last spring frost falls between May 16 and May 26, and the first fall frost between Sep 2 and Sep 11. The zone measures winter cold, not season length: humid Eastern and dry Western towns in the same zone can be weeks apart. Use your ZIP code for a planting date.
States with zone 2a
← Zone 1b (colder)Zone 2b (warmer) →
Questions
What is the temperature range of zone 2a?
Zone 2a covers places where the coldest night of an average winter (the annual extreme minimum averaged over 1991–2020) is −50 to −45 °F, or −45.6 to −42.8 °C.
When is the last frost in zone 2a?
Across ZIP codes in zone 2a, the median last spring frost falls between May 16 and May 26 for the middle half of places. Zone alone doesn't set the frost date — check your ZIP code.
Which states have zone 2a?
Zone 2a occurs in 1 state; the most ZIP codes are in Alaska.
What can I grow in zone 2a?
Perennials, shrubs and trees labeled hardy to zone 2a or a lower (colder) number should survive a typical winter. Annual vegetables depend on frost dates rather than zone.
Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.