When to plant in Lake Forest Park, WA
USDA Zone 9aLake Forest Park, Washington frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
With about 260 frost-free days, Lake Forest Park supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Zone 9a is warm enough that Lake Forest Park can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
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 Lake Forest Park’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 Lake Forest Park, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 24 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.
Lake Forest Park planting FAQ
When is the last spring frost in Lake Forest Park, WA?
Plan for the last spring frost in Lake Forest Park around March 8 (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 Lake Forest Park, WA?
The first fall frost in Lake Forest Park typically arrives around November 23 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Lake Forest Park in?
Lake Forest Park is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Lake Forest Park?
There are roughly 260 frost-free days in Lake Forest Park (a long growing season), running from the average last frost around March 8 to the first fall frost near November 23.
When should I plant tomatoes in Lake Forest Park?
In Lake Forest Park, start tomato seeds indoors around January 11–January 25, then transplant seedlings outdoors around March 15 once the danger of frost has passed.
Never miss a window in Lake Forest Park
An email when it’s time to start seeds, transplant, and sow — timed to Lake Forest Park’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Kenmore · 3 km
- Mountlake Terrace · 4 km
- Shoreline · 4 km
- Alderwood Manor · 6 km
- Bothell West · 6 km
- Bothell · 7 km
- Edmonds · 8 km
- Lynnwood · 8 km
Frost dates recorded at SEATTLE SAND PT WSFO, 8 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 Lake Forest Park, WA — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094290. Retrieved from https://blissgarden.com/washington/lake-forest-park.