When to plant in Prairie Ridge, WA
USDA Zone 8bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Prairie Ridge, Washington — all computed from Prairie Ridge's nearest NOAA weather station.
Zone 8b means many perennials and even some tender shrubs overwinter in Prairie Ridge, while your frost dates still decide when annuals go out.
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 Prairie Ridge’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 Prairie Ridge, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 15 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.
Prairie Ridge planting FAQ
When is the last spring frost in Prairie Ridge, WA?
Prairie Ridge's average last spring frost falls near April 11 — 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 Prairie Ridge, WA?
In Prairie Ridge, 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 Prairie Ridge in?
Prairie Ridge is in USDA hardiness zone 8b. In zone 8b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Prairie Ridge?
There are roughly 202 frost-free days in Prairie Ridge (a moderate growing season), running from the average last frost around April 11 to the first fall frost near October 30.
When should I plant tomatoes in Prairie Ridge?
In Prairie Ridge, start tomato seeds indoors around February 14–February 28, then transplant seedlings outdoors around April 18 once the danger of frost has passed.
Never miss a window in Prairie Ridge
An email when it’s time to start seeds, transplant, and sow — timed to Prairie Ridge’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Bonney Lake · 6 km
- Lake Tapps · 10 km
- South Hill · 11 km
- Sumner · 12 km
- Puyallup · 12 km
- Enumclaw · 13 km
- Edgewood · 15 km
- Graham · 16 km
Frost dates recorded at MCMILLIN RSVR, 9 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 Prairie Ridge, WA — Frost Dates & Zone 8b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00455224. Retrieved from https://blissgarden.com/washington/prairie-ridge.