USDA zone 7a in Washington
USDA plant hardiness zone 7a covers 49 locations across Washington (average annual extreme minimum 0 to 5 °F): Ashford, WA, Basin, WA, Brewster, WA, Cashmere, WA, Cle Elum, WA, Cliffdell, WA, and 43 more. Average last spring frost across this group ranges March 24 (Mattawa) to June 6 (Springdale), and growing seasons run 94–224 days (Springdale to Marblemount) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Washington location's own frost dates; the printable planting calendar uses Moses Lake, this group's median-season location.
- USDA zone
- 7a0 to 5 °F
- Last frost range
- Mar 24–Jun 6avg, 32°F
- First frost range
- Sep 11–Nov 14avg, 32°F
- Growing season range
- 94–224days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Ashford | — | Longmire Rainier Nps | May 22 | Oct 3 | 134 |
| Basin | Mesa | Eltopia 8 Wsw | Apr 21 | Oct 22 | 182 |
| Brewster | Bridgeport | Chief Joseph Dam | Apr 26 | Oct 11 | 167 |
| Cashmere | — | Leavenworth 3 S | May 10 | Sep 30 | 142 |
| Cle Elum | Roslyn, Ronald | Cle Elum | May 13 | Sep 25 | 132 |
| Cliffdell | Packwood | Packwood | Apr 30 | Oct 8 | 162 |
| Colfax | Albion | Pullman 2 Nw | May 6 | Sep 29 | 143 |
| College Place | Touchet | Whitman Mission | May 2 | Oct 1 | 151 |
| Colton | — | Pullman Moscow Rgnl Ap | Apr 29 | Oct 2 | 159 |
| Connell | — | Connell 1 W | Apr 30 | Oct 12 | 165 |
| Creston | — | Wilbur | Jun 1 | Sep 22 | 112 |
| Dayton | Waitsburg, Prescott | Dayton 1 Wsw | Apr 28 | Oct 13 | 168 |
| East Wenatchee | Rock Island | Wenatchee Pangborn Ap | Apr 8 | Oct 24 | 200 |
| Endicott | — | St John | Apr 29 | Oct 4 | 161 |
| Entiat | — | Entiat Fish Hatchery | Apr 5 | Oct 24 | 200 |
| Goldendale | — | Goldendale | May 19 | Sep 25 | 126 |
| Kahlotus | — | Hatton 9 Se | Apr 25 | Oct 15 | 173 |
| Keller | Electric, Elmer | Coulee Dam 1 Sw | Apr 22 | Oct 21 | 180 |
| Klickitat | — | Snowden | May 12 | Oct 11 | 149 |
| LaCrosse | Washtucna | Lacrosse | May 13 | Sep 26 | 133 |
| Leavenworth | Manson | Plain | May 22 | Sep 22 | 121 |
| Lind | Washtucna | Lind 3 Ne | May 7 | Oct 4 | 150 |
| Mabton | — | Prosser | Apr 14 | Oct 22 | 189 |
| Manson | Methow, Pateros | Methow 2 S | Apr 21 | Oct 15 | 177 |
| Manson | Chelan Falls | Chelan | Apr 17 | Oct 22 | 187 |
| Marblemount | — | Darrington 21 Nne | Apr 16 | Oct 25 | 192 |
| Marblemount | — | Newhalem | Apr 2 | Nov 14 | 224 |
| Mattawa | Schwana | Priest Rapids Dam | Mar 24 | Nov 4 | 222 |
| Moses Lake * | Othello, Warden | Moses Lake Grant Co Ap | Apr 27 | Oct 8 | 165 |
| Naches | Kittitas | Ellensburg | May 8 | Oct 2 | 146 |
| Okanogan | — | Omak Ap | Apr 30 | Oct 7 | 160 |
| Pasco | Burbank | Ice Harbor Dam | Apr 7 | Oct 22 | 199 |
| Pomeroy | — | Pomeroy | May 2 | Oct 4 | 155 |
| Quincy | George | Quincy | Apr 21 | Oct 16 | 178 |
| Roosevelt | — | Arlington | Apr 6 | Oct 21 | 196 |
| Roslyn | Snoqualmie Pass | Stampede Pass | May 14 | Oct 17 | 154 |
| Royal | — | Smyrna | Apr 23 | Oct 12 | 172 |
| Soap Lake | — | Ephrata Muni Ap | Apr 22 | Oct 17 | 175 |
| Spokane | — | Spokane Intl Ap | Apr 26 | Oct 12 | 168 |
| Spokane | Spokane Valley, Fairwood, Millwood | Spokane Felts Fld | Apr 26 | Oct 15 | 170 |
| Springdale | — | Davenport | Jun 6 | Sep 11 | 94 |
| Thorp | — | Ellensburg Bowers Fld | Apr 28 | Oct 7 | 163 |
| Toppenish | — | Wapato | Apr 21 | Oct 15 | 176 |
| Trout Lake | Glenwood | Mt Adams Rs | May 18 | Sep 25 | 125 |
| Uniontown | Genesee, Anatone | Lewiston Nez Perce Co Ap | Apr 6 | Oct 26 | 200 |
| Walla Walla | Dixie | Walla Walla Rgnl Ap | Mar 27 | Oct 31 | 219 |
| Wenatchee | Cashmere | Wenatchee | Apr 4 | Oct 28 | 208 |
| Yakima | Terrace Heights, Tampico, White Swan, Tieton, Cowiche, Harrah, +1 more | Yakima Air Terminal | May 8 | Oct 4 | 149 |
| Zillah | Granger, Buena | Moxee City 10 E | May 4 | Oct 10 | 155 |
* Moses Lake is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Moses Lake, representative)
Computed from Moses Lake's average frost dates — the median-season location in this Washingtonzone 7a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Mar 2 – Mar 16 | May 4 – May 11 | Jul 3 – Jul 23 | — | matures comfortably |
| Pepper | Very tender | Feb 16 – Mar 2 | May 11 – May 18 | Jul 10 – Aug 9 | — | matures comfortably |
| Cucumber | Tender | Mar 30 – Apr 6 | May 4 – May 11 | Jun 23 – Jul 13 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | May 4 – May 11 | Jun 18 – Jul 3 | — | matures comfortably |
| Bush bean | Tender | — | May 4 – May 11 | Jun 23 – Jul 3 | Aug 9 – Aug 19 | matures comfortably |
| Sweet corn | Tender | — | Apr 27 – May 11 | Jun 26 – Jul 26 | — | matures comfortably |
| Basil | Very tender | Mar 16 – Mar 30 | May 4 – May 11 | Jun 3 – Jun 18 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 16 – Mar 30 | Mar 30 – Apr 13 | May 14 – May 29 | Jul 26 – Aug 10 | matures comfortably |
| Pea | Hardy | — | Mar 16 – Mar 30 | May 10 – May 25 | Jul 16 – Jul 31 | matures comfortably |
| Spinach | Hardy | — | Mar 16 – Mar 30 | Apr 25 – May 5 | Aug 5 – Aug 15 | matures comfortably |
| Carrot | Half-hardy | — | Apr 6 – Apr 13 | Jun 5 – Jun 25 | Jul 6 – Jul 26 | matures comfortably |
| Broccoli | Half-hardy | Mar 2 – Mar 16 | Mar 30 – Apr 13 | May 24 – Jun 13 | Jul 11 – Jul 31 | matures comfortably |
Which crops fit this growing season
Using Moses Lake's own 165-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Moses Lake)
From NOAA's 1991–2020 Climate Normals at station USW00024110. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | May 9 | May 23 | Sep 29 | Oct 10 | 141 |
| 32°F (freeze) | Apr 27 | May 11 | Oct 8 | Oct 23 | 165 |
| 28°F | Apr 10 | Apr 30 | Oct 20 | Nov 5 | 191 |
| 24°F | Mar 16 | Apr 10 | Nov 1 | Nov 18 | 225 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 49 locations is 2,590; Moses Lake's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 2,772 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 4,989 | cool-season crops (brassicas, greens) |
Hardiness zone 7a in Washington
Zone 7a means an average annual extreme minimum winter temperature of about 0 to 5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Washington spans 8 hardiness zones in this dataset — see all Washington locations for the full range, including zones6a, 6b, 7b, 8a, 8b, 9a, 9b.
Explore zone 7a in other states at zone 7a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 7a mean in Washington?
- Zone 7a means an average annual extreme minimum winter temperature of 0 to 5 °F — the standard USDA measure of which perennials survive winter. 49 locations in Washington fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Washington's zone 7a is the growing season longest?
- Marblemount runs the longest season on this page at about 224 days; Springdale is shortest at about 94 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Washington's zone 7a?
- Using Moses Lake's frost dates (this page's median-season location): start seeds indoors about Mar 2 – Mar 16, then transplant outside about May 4 – May 11. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Washington's zone 7a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 49 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.