When to plant in Shoreline, WA
USDA Zone 9aShoreline, Washington frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Shoreline enjoys a long ~260-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. In zone 9a, frost is a minor factor for Shoreline — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
SEATTLE SAND PT WSFO · 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 Shoreline’s own odds, recorded at SEATTLE SAND PT WSFO.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 26 | Apr 4 | Mar 17 | Oct 24 | Nov 5 | Nov 22 |
| 32°F | Mar 29 | Mar 8 | Feb 13 | Nov 4 | Nov 23 | Dec 16 |
| 28°F | Mar 1 | Feb 11 | Dec 27 | Nov 17 | Dec 11 | Jan 17 |
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 Shoreline, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 25 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.
Shoreline planting FAQ
When is the last spring frost in Shoreline, WA?
Shoreline's average last spring frost falls near March 8 — 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 Shoreline, WA?
Expect Shoreline's first fall frost near November 23 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Shoreline in?
Shoreline is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Shoreline?
Shoreline has about 260 frost-free days — a long growing season — between the average last spring frost (March 8) and first fall frost (November 23).
When should I plant tomatoes in Shoreline?
For Shoreline, sow tomatoes indoors about January 11–January 25 and move the seedlings out around March 15, after the last spring frost.
Never miss a window in Shoreline
An email when it’s time to start seeds, transplant, and sow — timed to Shoreline’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Lake Forest Park · 4 km
- Mountlake Terrace · 5 km
- Edmonds · 6 km
- Kenmore · 7 km
- Alderwood Manor · 9 km
- Lynnwood · 9 km
- Bothell West · 10 km
- Bothell · 11 km
Frost dates recorded at SEATTLE SAND PT WSFO, 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 Shoreline, WA — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094290. Retrieved from https://blissgarden.com/washington/shoreline.