In Washington, the last spring frost usually comes between March 17 and May 21, and the first fall frost between September 19 and November 13, depending on where you live. Most of Washington is in USDA hardiness zones 6b to 9a.
Find the frost dates for your ZIP code
Frost dates from NOAA 1991–2020 U.S. Climate Normals, nearest weather station. Zones derived from the 2023 USDA Plant Hardiness Zone Map data (PRISM Climate Group, Oregon State University). This is not the official USDA Plant Hardiness Zone Map.
Frost dates for Washington cities
Dates come from the NOAA weather station closest to each city. The last spring frost and first fall frost are the typical dates, with a 30% chance of frost after (or before) them. The safer planting date has only a 10% chance of a later spring frost: use it for tender plants like tomatoes, peppers and basil.
| City | Zone | Last frost | Safer date | First frost |
|---|---|---|---|---|
| Seattle | 9a | March 21 | April 1 | Nov. 10 |
| Spokane | 7a | May 2 | May 10 | Oct. 6 |
| Tacoma | 8b | March 17 | March 31 | Nov. 7 |
| Vancouver | 8b | May 1 | May 10 | Oct. 10 |
| Everett | 8b | April 1 | April 11 | Oct. 27 |
| Yakima | 7a | April 18 | April 28 | Oct. 17 |
| Bellingham | 8b | April 8 | April 24 | Oct. 26 |
| Kennewick | 7b | April 2 | April 10 | Oct. 25 |
| Olympia | 8b | May 5 | May 15 | Oct. 6 |
| Longview | 8b | April 20 | May 2 | Oct. 29 |
Frost dates vary a lot across Washington. Among the cities above, Tacoma has the earliest last frost (around March 17) and Olympia the latest (around May 5), about 7 weeks apart. Elevation, nearby water and local terrain all make a difference, so use the dates for the place closest to you, or look up your ZIP code.
Growing zones in Washington
Most of Washington is in USDA hardiness zones 6b to 9a. A typical frost-free growing season lasts about 205 days, longer in the warmest areas and shorter in the coldest.
Find planting dates for the main zones in Washington:
- Zone 6 (about 17% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
- Zone 7 (about 23% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
- Zone 8 (about 43% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
- Zone 9 (about 17% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
See all crops in our planting guides, or build a planting calendar for your ZIP code.
How to use frost dates
- Cool-season crops such as peas, lettuce, spinach and onions can go in several weeks before your last spring frost.
- Warm-season crops such as tomatoes, peppers, squash and beans wait until after it, when the soil has warmed.
- Fall crops are timed back from your first fall frost, and garlic and tulips are planted around it.
- Frost dates are averages. Check the forecast before setting out tender plants.
Frequently asked questions
When is the last frost in Washington?
It depends on where you live. Across most of Washington, the last spring frost comes between March 17 and May 21. In Seattle, it is around March 21.
When is the first frost in Washington?
Across most of Washington, the first fall frost comes between September 19 and November 13. In Seattle, it is around November 10.
What planting zone is Washington?
Most of Washington is in USDA hardiness zones 6b to 9a. Enter your ZIP code above to find your exact zone.
When can I plant tomatoes in Washington?
Plant tomatoes outside after your last frost, once nights stay above 50 °F. In Seattle, the safer date, with only a 10% chance of a later frost, is around April 1. See when to plant tomatoes in zone 9.
Sources. Frost dates come from the nearest NOAA weather station to each city or ZIP code. Zones come from the 2023 USDA Plant Hardiness Zone Map ZIP code data. Our zone lookup is not the official USDA map.