When to plant in Tucson, AZ
USDA Zone 9bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Tucson, Arizona — all computed from Tucson's nearest NOAA weather station.
Tucson enjoys a long ~307-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 9b, frost is a minor factor for Tucson — most perennials thrive, and annual vegetables can go out early and stay late.
The average last spring frost in Tucson is now 7 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
TUCSON INTL AP · 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 Tucson’s own odds, recorded at TUCSON INTL AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 24 | Feb 28 | Feb 3 | Nov 11 | Nov 26 | Dec 14 |
| 32°F | Mar 2 | Feb 5 | Jan 4 | Nov 21 | Dec 9 | Jan 3 |
| 28°F | Feb 17 | Jan 11 | Dec 14 | Nov 30 | Dec 26 | Feb 1 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in Tucson, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 13 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.
Tucson planting FAQ
When is the last spring frost in Tucson, AZ?
Tucson's average last spring frost falls near February 5 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Tucson, AZ?
The first fall frost in Tucson typically arrives around December 9 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Tucson in?
Tucson is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Tucson?
Tucson has about 307 frost-free days — a long growing season — between the average last spring frost (February 5) and first fall frost (December 9).
When should I plant tomatoes in Tucson?
For Tucson, sow tomatoes indoors about December 11–December 25 and move the seedlings out around February 12, after the last spring frost.
Never miss a window in Tucson
An email when it’s time to start seeds, transplant, and sow — timed to Tucson’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Catalina Foothills · 17 km
- Drexel Heights · 17 km
- Tanque Verde · 18 km
- Flowing Wells · 20 km
- Vail · 22 km
- Valencia West · 23 km
- Tucson Mountains · 24 km
- Tucson Estates · 24 km
Frost dates recorded at TUCSON INTL AP, 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 Tucson, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00023160. Retrieved from https://blissgarden.com/arizona/tucson.