Washington Planting Zones by City and ZIP Code
Washington runs from zones 6a to 9b; 37% of its ZIPs are 8b, Seattle is 9a and Spokane is 7a.
Washington runs from zones 6a to 9b
The coldest night of the winter averages -10°F to -5°F in the coldest of Washington’s ZIP codes and 25°F to 30°F in the warmest. Most of the state is zone 8b.
Planting zones of Washington cities
| City | Zone | Coldest night, on average | Since 2012 |
|---|---|---|---|
| Seattle98101 | 9a | 20°F to 25°F | half a zone warmer than 2012 (8b) |
| Spokane99201 | 7a | 0°F to 5°F | half a zone warmer than 2012 (6b) |
| Tacoma98402 | 8b | 15°F to 20°F | same as 2012 |
| Yakima98901 | 7a | 0°F to 5°F | half a zone warmer than 2012 (6b) |
| Bellingham98225 | 8b | 15°F to 20°F | half a zone warmer than 2012 (8a) |
| Walla Walla99362 | 7a | 0°F to 5°F | same as 2012 |
Tap a ZIP for that address’s frost dates and this month’s jobs.
Find your zone anywhere in Washington
A ZIP code or a town gives you its zone, how it moved since 2012, the frost dates at the nearest NOAA station, and the jobs for this month timed from them.
What to plant in Washington this month
The calendar for each of Washington's main zones, from vegetables to pruning and winter protection, each job tied to the extension page it comes from. Pick a month, or read the whole year below it.
Timed from the median frost dates of the 37 NOAA stations in Washington’s zone 8b: last spring frost Apr 7, first fall frost Nov 2. Your own ZIP’s frost dates move every window, so the ZIP tool times them for you.
Pick a month above to see every job in it.
The year at a glance
- Start vegetable seeds indoorsDec to Mar
- Sow vegetables in the gardenMar to Apr
- Sow the fall vegetable gardenJul to Sep
- Set out transplantsMar to Apr
- Plant trees and shrubsSep 21 to Apr 21
- Plant garlicOct 19 to Nov 23
- Plant pre-chilled tulip bulbsNov 20 to Dec 31
- Divide fall-blooming perennialsMar 17 to Apr 28
- Divide spring and summer-blooming perennialsSep 21 to Nov 2
- Prune trees and summer-flowering shrubs while dormantFeb 24 to Apr 7
- Prune spring-flowering shrubs after they bloomMar 24 to May 19
- Prune out cold damageApr 7 to May 19
- Cover tender plants on a freezing nightOct 26 to Apr 7
- Cut back perennials after a hard freezeNov 9 to Dec 7
What changed in Washington since 2012
Every ZIP on both mapsCompared ZIP by ZIP from the 2023 and 2012 USDA tables; 708 Washington ZIP codes appear in both.
Why Washington’s zones moved
Of the cities above, Seattle went from 8b to 9a, Spokane went from 6b to 7a, Yakima went from 6b to 7a and Bellingham went from 8a to 8b.
The USDA explains the national picture: “When compared to the 2012 map, the 2023 version reveals that about half of the country shifted to the next warmer half zone, and the other half of the country remained in the same half zone.” The new map uses 1991 to 2020 and more than 13,000 weather stations, so it draws Washington’s hills, valleys and cities more finely than the 2012 map did.
A warmer zone changes which perennials and shrubs come through the winter, not when the garden gets planted; that still follows the frost dates.
Frost dates and seed starting in Washington
Washington planting zone questions
Planting zones by state
Sources. USDA Plant Hardiness Zone Map, ZIP code tables (2023 and 2012), PRISM Climate Group, Oregon State University; USDA Plant Hardiness Zone Map; USDA Unveils Updated Plant Hardiness Zone Map (USDA Agricultural Research Service, November 15, 2023); NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal, by station (v1.0.1); NC State Extension Gardener Plant Toolbox. Zones are read from the PRISM ZIP code tables, read Oct 9, 2026; a ZIP code’s zone is the zone at its center. The calendar’s extension sources are listed on the planting zones page and under each job.