Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated
Hardiness zones 1a to 13b
Each USDA hardiness zone is a 10 °F band of the average coldest winter night, split into a colder “a” and a warmer “b” half. The 2023 map is based on 1991–2020 weather.
Zone chart
1a−60 to −55 °F51b−55 to −50 °F112a−50 to −45 °F272b−45 to −40 °F173a−40 to −35 °F233b−35 to −30 °F2304a−30 to −25 °F8144b−25 to −20 °F1,2845a−20 to −15 °F2,4265b−15 to −10 °F2,8806a−10 to −5 °F5,1876b−5 to 0 °F5,2717a0 to 5 °F4,8777b5 to 10 °F3,8558a10 to 15 °F3,4138b15 to 20 °F3,3799a20 to 25 °F2,1999b25 to 30 °F2,08510a30 to 35 °F1,23410b35 to 40 °F75211a40 to 45 °F20511b45 to 50 °F1612a50 to 55 °F3012b55 to 60 °F13613a60 to 65 °F10113b65 to 70 °F26
Bars: number of U.S. ZIP codes in each zone.
Temperature table
| Zone | Coldest night °F | °C | ZIP codes |
|---|---|---|---|
| 1a | −60 to −55 °F | −51.1 to −48.3 °C | 5 |
| 1b | −55 to −50 °F | −48.3 to −45.6 °C | 11 |
| 2a | −50 to −45 °F | −45.6 to −42.8 °C | 27 |
| 2b | −45 to −40 °F | −42.8 to −40 °C | 17 |
| 3a | −40 to −35 °F | −40 to −37.2 °C | 23 |
| 3b | −35 to −30 °F | −37.2 to −34.4 °C | 230 |
| 4a | −30 to −25 °F | −34.4 to −31.7 °C | 814 |
| 4b | −25 to −20 °F | −31.7 to −28.9 °C | 1,284 |
| 5a | −20 to −15 °F | −28.9 to −26.1 °C | 2,426 |
| 5b | −15 to −10 °F | −26.1 to −23.3 °C | 2,880 |
| 6a | −10 to −5 °F | −23.3 to −20.6 °C | 5,187 |
| 6b | −5 to 0 °F | −20.6 to −17.8 °C | 5,271 |
| 7a | 0 to 5 °F | −17.8 to −15 °C | 4,877 |
| 7b | 5 to 10 °F | −15 to −12.2 °C | 3,855 |
| 8a | 10 to 15 °F | −12.2 to −9.4 °C | 3,413 |
| 8b | 15 to 20 °F | −9.4 to −6.7 °C | 3,379 |
| 9a | 20 to 25 °F | −6.7 to −3.9 °C | 2,199 |
| 9b | 25 to 30 °F | −3.9 to −1.1 °C | 2,085 |
| 10a | 30 to 35 °F | −1.1 to 1.7 °C | 1,234 |
| 10b | 35 to 40 °F | 1.7 to 4.4 °C | 752 |
| 11a | 40 to 45 °F | 4.4 to 7.2 °C | 205 |
| 11b | 45 to 50 °F | 7.2 to 10 °C | 16 |
| 12a | 50 to 55 °F | 10 to 12.8 °C | 30 |
| 12b | 55 to 60 °F | 12.8 to 15.6 °C | 136 |
| 13a | 60 to 65 °F | 15.6 to 18.3 °C | 101 |
| 13b | 65 to 70 °F | 18.3 to 21.1 °C | 26 |
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.