When to plant in Oak Harbor, WA
USDA Zone 8bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Oak Harbor, Washington — all computed from Oak Harbor's nearest NOAA weather station.
Oak Harbor enjoys a long ~246-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 8b, Oak Harbor supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
The average last spring frost in Oak Harbor is now 13 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
WHIDBEY ISLAND NAS · 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 Oak Harbor’s own odds, recorded at WHIDBEY ISLAND NAS.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 29 | Apr 9 | Mar 22 | Oct 6 | Oct 28 | Nov 17 |
| 32°F | Apr 1 | Mar 13 | Feb 20 | Oct 26 | Nov 14 | Dec 5 |
| 28°F | Mar 12 | Feb 18 | Jan 5 | Nov 9 | Dec 1 | Jan 6 |
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 Oak Harbor, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 22 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.
Oak Harbor planting FAQ
When is the last spring frost in Oak Harbor, WA?
Plan for the last spring frost in Oak Harbor around March 13 (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 Oak Harbor, WA?
Expect Oak Harbor's first fall frost near November 14 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Oak Harbor in?
Oak Harbor is in USDA hardiness zone 8b. In zone 8b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Oak Harbor?
Oak Harbor has about 246 frost-free days — a long growing season — between the average last spring frost (March 13) and first fall frost (November 14).
When should I plant tomatoes in Oak Harbor?
For Oak Harbor, sow tomatoes indoors about January 16–January 30 and move the seedlings out around March 20, after the last spring frost.
Never miss a window in Oak Harbor
An email when it’s time to start seeds, transplant, and sow — timed to Oak Harbor’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Camano · 20 km
- Anacortes · 22 km
- Port Townsend · 22 km
- Mount Vernon · 27 km
- Burlington · 29 km
- Sedro-Woolley · 38 km
- Arlington · 38 km
- Marysville · 42 km
Frost dates recorded at WHIDBEY ISLAND NAS, 7 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 Oak Harbor, WA — Frost Dates & Zone 8b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00024255. Retrieved from https://blissgarden.com/washington/oak-harbor.