When to plant in Sumner, WA
USDA Zone 8bSumner, Washington frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
In zone 8b, Sumner supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
MCMILLIN RSVR · 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 Sumner’s own odds, recorded at MCMILLIN RSVR.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 17 | May 1 | Apr 17 | Sep 30 | Oct 12 | Oct 31 |
| 32°F | Apr 29 | Apr 11 | Mar 23 | Oct 13 | Oct 30 | Nov 17 |
| 28°F | Apr 8 | Mar 16 | Feb 19 | Oct 28 | Nov 14 | Dec 8 |
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 Sumner, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 19 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.
Sumner planting FAQ
When is the last spring frost in Sumner, WA?
Plan for the last spring frost in Sumner around April 11 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Sumner, WA?
Expect Sumner's first fall frost near October 30 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Sumner in?
Sumner is in USDA hardiness zone 8b. In zone 8b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Sumner?
Sumner has about 202 frost-free days — a moderate growing season — between the average last spring frost (April 11) and first fall frost (October 30).
When should I plant tomatoes in Sumner?
For Sumner, sow tomatoes indoors about February 14–February 28 and move the seedlings out around April 18, after the last spring frost.
Never miss a window in Sumner
An email when it’s time to start seeds, transplant, and sow — timed to Sumner’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Edgewood · 4 km
- Lake Tapps · 5 km
- Bonney Lake · 6 km
- Lakeland South · 7 km
- Puyallup · 7 km
- Fife · 9 km
- Auburn · 9 km
- Prairie Ridge · 12 km
Frost dates recorded at MCMILLIN RSVR, 10 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 Sumner, WA — Frost Dates & Zone 8b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00455224. Retrieved from https://blissgarden.com/washington/sumner.