Spokane Valley, Washington: planting zone & frost dates
Spokane Valley is in USDA plant hardiness zone 7a, where the average coldest winter night reaches 0 to 5°F (-17.8 to -15.0°C). The typical last spring frost is around May 1 and the first fall frost around Oct 7.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 10 | Sep 30 |
| Typical planning date (30% risk) | May 1 | Oct 7 |
| Median (50%) | Apr 26 | Oct 15 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station SPOKANE FELTS FLD, WA (USW00094176), 4.3 mi (7.0 km) from the city center and 92 ft lower than the city center (-28 m). Record used for the 1991–2020 normals: 22 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Spokane Valley
Spokane Valley spans more than one half-zone. Share of the city's land area by zone (via its 6 ZIP codes): 7a (87%), 6b (13%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Spokane Valley
Dates are counted from the 30%-risk frost dates above (last frost May 1, first frost Oct 7). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Mar 6 – Mar 20 | May 8 – May 22 | — | — |
| Pepper | Feb 20 – Mar 6 | May 15 – May 29 | — | — |
| Lettuce | Mar 20 – Apr 3 | Apr 17 – May 8 | Apr 3 – May 15 | Jul 29 – Aug 26 |
| Green Beans | — | — | May 8 – Jun 12 | Jul 15 – Jul 29 |
| Sweet Corn | — | — | May 8 – Jun 5 | — |
| Zucchini & Summer Squash | Apr 3 – Apr 10 | May 8 – May 22 | May 8 – May 29 | Jul 15 – Jul 29 |
| Cucumber | Apr 3 – Apr 10 | May 15 – May 22 | May 8 – May 29 | Jul 15 – Jul 29 |
| Carrot | — | — | Apr 10 – May 15 | Jul 15 – Jul 29 |
| Onion | Feb 6 – Feb 20 | Apr 3 – Apr 17 | — | — |
| Potato | — | Apr 3 – Apr 24 | — | — |
| Basil | Mar 20 – Apr 3 | May 15 – May 29 | May 15 – Jun 5 | — |
| Spinach | — | — | Mar 20 – Apr 17 | Aug 12 – Sep 9 |
| Kale | Mar 6 – Mar 20 | Apr 3 – Apr 24 | Apr 3 – Apr 24 | Jul 29 – Aug 26 |
| Broccoli | Mar 6 – Mar 20 | Apr 17 – May 8 | — | Jul 15 – Jul 29 |
| Peas | — | — | Mar 20 – Apr 10 | Jul 29 – Aug 12 |
| Eggplant | Feb 20 – Mar 6 | May 15 – May 29 | — | — |
| Cabbage | Mar 6 – Mar 20 | Apr 3 – Apr 17 | — | Jul 15 – Jul 29 |
| Radish | — | — | Mar 27 – May 15 | Aug 26 – Sep 23 |
| Strawberry | — | Apr 3 – Apr 24 | — | — |
| Beets | — | — | Apr 10 – May 22 | Jul 29 – Aug 12 |
Nearby cities in Washington
- Spokane — zone 6b, last frost May 1, first frost Oct 7
- Pasco — zone 7a, last frost May 2, first frost Oct 4
- Kennewick — zone 7b, last frost Apr 2, first frost Oct 25
- Yakima — zone 7a, last frost Apr 18, first frost Oct 17
- Redmond — zone 8b, last frost Mar 16, first frost Nov 15
- Bellevue — zone 8b, last frost Mar 16, first frost Nov 15
More: all Washington cities · other zone 7a cities: Louisville, KY, Wichita, KS, Cleveland, OH, Lexington, KY, St. Louis, MO, Boise, ID, Amarillo, TX, Providence, RI
Spokane Valley gardening questions
When is the last frost in Spokane Valley, WA?
Plan around May 1. At NOAA's Spokane Felts Field, WA station, 4.3 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 26, and after May 10 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 4. The 90% and 10% dates are 30 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Spokane Valley, WA?
Start seeds indoors Mar 6 – Mar 20 and set transplants outside May 8 – May 22, once nights stay above 50°F and the soil is near 60°F. That leaves 159 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Spokane Valley?
About 170 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 149 days, and in 1 year in 10 it runs 193 days or more. In fall there is a 10% chance of frost by Sep 30 and a 30% chance by Oct 7. That ranks 17th longest of 18 Washington cities on this site.
When should I plant a fall garden in Spokane Valley?
Count back from the first fall frost (Oct 7): transplant broccoli Jul 15 – Jul 29; sow kale Jul 29 – Aug 26; sow lettuce Jul 29 – Aug 26; sow radishes Aug 26 – Sep 23. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Oct 27. How the math works: succession and fall planting.
Did Spokane Valley's hardiness zone change on the 2023 map?
Yes. Most of Spokane Valley was zone 6b on the 2012 map and is zone 7a on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
Is all of Spokane Valley in zone 7a?
No. Zone 7a covers about 87% of the city's land; the rest is in 6b (13%), measured across the city's 6 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.