When to plant in Portland, OR
USDA Zone 8bEverything below — frost dates, hardiness zone, and what to plant when in Portland, Oregon — is derived from the closest NOAA station with complete climate normals.
A generous ~279-day season lets Portland gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 8b means many perennials and even some tender shrubs overwinter in Portland, while your frost dates still decide when annuals go out.
Frost probability
PORTLAND KGW-TV · 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 Portland’s own odds, recorded at PORTLAND KGW-TV.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 21 | Mar 29 | Mar 7 | Oct 28 | Nov 12 | Dec 1 |
| 32°F | Mar 21 | Feb 25 | Jan 24 | Nov 10 | Dec 1 | Dec 27 |
| 28°F | Feb 26 | Jan 31 | Dec 21 | Nov 25 | Dec 20 | Jan 30 |
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 Portland, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 9 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.
Portland planting FAQ
When is the last spring frost in Portland, OR?
On average, the last spring frost in Portland is around February 25 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Portland, OR?
Expect Portland's first fall frost near December 1 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Portland in?
Portland is in USDA hardiness zone 8b. In zone 8b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Portland?
There are roughly 279 frost-free days in Portland (a long growing season), running from the average last frost around February 25 to the first fall frost near December 1.
When should I plant tomatoes in Portland?
In Portland, start tomato seeds indoors around December 31–January 14, then transplant seedlings outdoors around March 4 once the danger of frost has passed.
Never miss a window in Portland
An email when it’s time to start seeds, transplant, and sow — timed to Portland’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Milwaukie · 10 km
- Cedar Mill · 12 km
- Vancouver · 12 km
- Minnehaha · 14 km
- Oak Grove · 14 km
- Lake Oswego · 14 km
- Oatfield · 15 km
- Beaverton · 15 km
Frost dates recorded at PORTLAND KGW-TV, 4 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 Portland, OR — Frost Dates & Zone 8b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00356749. Retrieved from https://blissgarden.com/oregon/portland.