USDA hardiness zone 2a
In zone 2a, the average annual extreme minimum temperature is -50 to -45°F (-45.6 to -42.8°C), based on 1991–2020 data from the 2023 USDA Plant Hardiness Zone Map.
What zone 2a means for your garden
A plant labeled "hardy to zone 2a" should survive a typical winter low of -50°F. Only very cold-hardy perennials survive; look for plants rated to this zone or colder, and use season-extension for vegetables. Zone 2b is the warmer half of zone 2.
ZIP codes in zone 2a: 27 in Alaska. New to zones? Read how to read your hardiness zone.
Frost dates in zone 2a
Across 1 major cities in zone 2a, the 30%-risk last spring frost ranges from May 21 to May 21 (median May 21), and the first fall frost has a median of Sep 1. Frost timing depends on elevation, latitude and distance from water — a zone does not set a frost date, so check your city page for local dates.
Typical planting calendar for zone 2a
Based on the median frost dates above. For your exact dates, use your city page.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato Short season (103 frost-free days): choose early varieties. | Mar 26 – Apr 9 | May 28 – Jun 11 | — | — |
| Pepper Short season (103 frost-free days): choose early varieties. | Mar 12 – Mar 26 | Jun 4 – Jun 18 | — | — |
| Lettuce | Apr 9 – Apr 23 | May 7 – May 28 | Apr 23 – Jun 4 | Jun 23 – Jul 21 |
| Green Beans | — | — | May 28 – Jul 2 | — |
| Sweet Corn Short season (103 frost-free days): choose early varieties. | — | — | May 28 – Jun 25 | — |
| Zucchini & Summer Squash | Apr 23 – Apr 30 | May 28 – Jun 11 | May 28 – Jun 18 | — |
| Cucumber | Apr 23 – Apr 30 | Jun 4 – Jun 11 | May 28 – Jun 18 | — |
| Carrot | — | — | Apr 30 – Jun 4 | — |
| Onion | Feb 26 – Mar 12 | Apr 23 – May 7 | — | — |
| Potato | — | Apr 23 – May 14 | — | — |
| Basil Short season (103 frost-free days): choose early varieties. | Apr 9 – Apr 23 | Jun 4 – Jun 18 | Jun 4 – Jun 25 | — |
| Spinach | — | — | Apr 9 – May 7 | Jul 7 – Aug 4 |
| Kale | Mar 26 – Apr 9 | Apr 23 – May 14 | Apr 23 – May 14 | Jun 23 – Jul 21 |
| Broccoli | Mar 26 – Apr 9 | May 7 – May 28 | — | — |
| Peas | — | — | Apr 9 – Apr 30 | Jun 23 – Jul 7 |
| Eggplant Short season (103 frost-free days): choose early varieties. | Mar 12 – Mar 26 | Jun 4 – Jun 18 | — | — |
| Cabbage | Mar 26 – Apr 9 | Apr 23 – May 7 | — | — |
| Radish | — | — | Apr 16 – Jun 4 | Jul 21 – Aug 18 |
| Strawberry | — | Apr 23 – May 14 | — | — |
| Beets | — | — | Apr 30 – Jun 11 | Jun 23 – Jul 7 |
Cities in zone 2a (1)
Major cities whose center falls in zone 2a:
- Fairbanks, AK — last frost May 21, first frost Sep 1
← Zone 1b · Zone 2b → · All zones
Zone 2a questions
How cold does it get in zone 2a?
Zone 2a is defined by an average annual extreme minimum temperature of -50 to -45°F (-45.6 to -42.8°C) for 1991–2020 — the average of each year's single coldest night, not the record low. Individual winters can be colder, so plants rated exactly for zone 2a carry some risk in a severe year.
When is the last frost in zone 2a?
Roughly May 21 for spring and Sep 1 for the first fall frost (median of 1 major cities). Treat these as rough: frost dates swing widely with elevation.
Which states have zone 2a?
The 2023 listings put 27 ZIP codes in zone 2a, spread over 1 states and territories. The most are in Alaska (27).
Did zone 2a grow on the 2023 map?
No: 33 ZIP codes were in zone 2a on the 2012 map and 27 are on the 2023 map (-6). Of today's zone 2a ZIP codes that were also listed in 2012, 33% were in a colder zone then, 52% were already 2a, and 15% were in a warmer zone. What changed in 2023.
Which big cities are in zone 2a?
The largest cities on this site in zone 2a are Fairbanks, AK; 1 cities in all are listed below.