When to plant in Oro Valley, AZ
USDA Zone 9aEverything below — frost dates, hardiness zone, and what to plant when in Oro Valley, Arizona — is derived from the closest NOAA station with complete climate normals.
In zone 9a, frost is a minor factor for Oro Valley — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
CATALINA SP · 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 Oro Valley’s own odds, recorded at CATALINA SP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 5 | Apr 18 | Apr 4 | Oct 18 | Nov 1 | Nov 17 |
| 32°F | Apr 18 | Apr 2 | Mar 16 | Oct 26 | Nov 11 | Nov 29 |
| 28°F | Apr 1 | Mar 12 | Feb 22 | Nov 3 | Nov 21 | Dec 10 |
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 Oro Valley, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 16 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.
Oro Valley planting FAQ
When is the last spring frost in Oro Valley, AZ?
On average, the last spring frost in Oro Valley is around April 2 (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 Oro Valley, AZ?
The first fall frost in Oro Valley typically arrives around November 11 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Oro Valley in?
Oro Valley is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Oro Valley?
Oro Valley has about 223 frost-free days — a long growing season — between the average last spring frost (April 2) and first fall frost (November 11).
When should I plant tomatoes in Oro Valley?
For Oro Valley, sow tomatoes indoors about February 5–February 19 and move the seedlings out around April 9, after the last spring frost.
Never miss a window in Oro Valley
An email when it’s time to start seeds, transplant, and sow — timed to Oro Valley’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Casas Adobes · 9 km
- Flowing Wells · 14 km
- Marana · 16 km
- Catalina Foothills · 16 km
- Saddlebrooke · 18 km
- Tucson Mountains · 18 km
- Tanque Verde · 28 km
- Tucson Estates · 30 km
Frost dates recorded at CATALINA SP, 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 Oro Valley, AZ — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00021357. Retrieved from https://blissgarden.com/arizona/oro-valley.