When to plant in Kennewick, WA
USDA Zone 7bEverything below — frost dates, hardiness zone, and what to plant when in Kennewick, Washington — is derived from the closest NOAA station with complete climate normals.
In zone 7b, Kennewick supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
KENNEWICK · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Kennewick’s own odds, recorded at KENNEWICK.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 30 | Apr 14 | Mar 30 | Oct 7 | Oct 21 | Nov 2 |
| 32°F | Apr 10 | Mar 28 | Mar 9 | Oct 18 | Oct 30 | Nov 15 |
| 28°F | Mar 29 | Mar 8 | Feb 20 | Oct 27 | Nov 11 | Dec 1 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Kennewick, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 14 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Kennewick planting FAQ
When is the last spring frost in Kennewick, WA?
Kennewick's average last spring frost falls near March 28 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Kennewick, WA?
In Kennewick, the first 32°F freeze of fall lands around October 30 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Kennewick in?
Kennewick is in USDA hardiness zone 7b. In zone 7b, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Kennewick?
Kennewick has about 216 frost-free days — a long growing season — between the average last spring frost (March 28) and first fall frost (October 30).
When should I plant tomatoes in Kennewick?
For Kennewick, sow tomatoes indoors about January 31–February 14 and move the seedlings out around April 4, after the last spring frost.
Never miss a window in Kennewick
An email when it’s time to start seeds, transplant, and sow — timed to Kennewick’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Pasco · 9 km
- Richland · 13 km
- West Richland · 21 km
- Hermiston · 41 km
- Grandview · 57 km
- Pendleton · 64 km
- Sunnyside · 65 km
- Walla Walla · 66 km
Frost dates recorded at KENNEWICK, 6 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Kennewick, WA — Frost Dates & Zone 7b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00454154. Retrieved from https://blissgarden.com/washington/kennewick.