When to plant in Aloha, OR
USDA Zone 9aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Aloha, Oregon — all computed from Aloha's nearest NOAA weather station.
A generous ~297-day season lets Aloha gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9a is warm enough that Aloha can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
NATURE PARK-BEAVERTON · 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 Aloha’s own odds, recorded at NATURE PARK-BEAVERTON.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 15 | Mar 23 | Feb 25 | Oct 26 | Nov 13 | Dec 4 |
| 32°F | Mar 5 | Feb 11 | Dec 26 | Nov 11 | Dec 5 | Jan 12 |
| 28°F | Feb 16 | Jan 6 | Dec 2 | Nov 24 | Dec 21 | Feb 5 |
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 Aloha, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 8 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.
Aloha planting FAQ
When is the last spring frost in Aloha, OR?
On average, the last spring frost in Aloha is around February 11 (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 Aloha, OR?
The first fall frost in Aloha typically arrives around December 5 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Aloha in?
Aloha is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Aloha?
There are roughly 297 frost-free days in Aloha (a long growing season), running from the average last frost around February 11 to the first fall frost near December 5.
When should I plant tomatoes in Aloha?
In Aloha, start tomato seeds indoors around December 17–December 31, then transplant seedlings outdoors around February 18 once the danger of frost has passed.
Never miss a window in Aloha
An email when it’s time to start seeds, transplant, and sow — timed to Aloha’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at NATURE PARK-BEAVERTON, 3 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 Aloha, OR — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00355945. Retrieved from https://blissgarden.com/oregon/aloha.