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USDA Plant Hardiness Zones (2023)
Each zone is defined by the average annual extreme minimum temperature at that location. Zones step in 5°F increments; sub-zones (a / b) split each zone in 5°F halves. Knowing your zone is the starting point for picking perennials, choosing planting dates, and reading seed-packet hardiness ranges.
Hardiness zone sample
32 representative zips, sorted from coldest to warmest.
| Zip | Zone | Min temp (°F) | Max temp (°F) | Visual range |
|---|---|---|---|---|
99723 |
1a | -60 | -55 | |
99701 |
2a | -50 | -45 | |
58102 |
4a | -30 | -25 | |
55111 |
5a | -20 | -15 | |
99502 |
5a | -20 | -15 | |
05401 |
5b | -15 | -10 | |
60666 |
6a | -10 | -5 | |
80249 |
6a | -10 | -5 | |
15231 |
6b | -5 | 0 | |
48242 |
6b | -5 | 0 | |
64153 |
6b | -5 | 0 | |
02128 |
7a | 0 | 5 | |
83705 |
7a | 0 | 5 | |
84122 |
7a | 0 | 5 | |
99801 |
7a | 0 | 5 | |
11371 |
7b | 5 | 10 | |
87106 |
7b | 5 | 10 | |
30320 |
8a | 10 | 15 | |
75261 |
8a | 10 | 15 | |
29406 |
9a | 20 | 25 | |
77032 |
9a | 20 | 25 | |
89119 |
9a | 20 | 25 | |
97218 |
9a | 20 | 25 | |
98158 |
9a | 20 | 25 | |
70126 |
9b | 25 | 30 | |
85034 |
10a | 30 | 35 | |
94128 |
10a | 30 | 35 | |
90045 |
10b | 35 | 40 | |
92101 |
10b | 35 | 40 | |
33172 |
11a | 40 | 45 | |
96819 |
12b | 55 | 60 | |
96910 |
13a | 60 | 65 |
Source
USDA 2023 Plant Hardiness Zone Map, hosted by the PRISM Climate Group at Oregon State University. The map is the official US gardening reference; zones are recomputed from a 30-year window of station-level extreme-minimum data.
Source: USDA / PRISM Climate Group, Oregon State University.