When to plant in Phoenix, AZ
USDA Zone 9bPhoenix, Arizona frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
With about 351 frost-free days, Phoenix supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. In zone 9b, frost is a minor factor for Phoenix — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
PHOENIX DEER VALLEY MUNI 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 Phoenix’s own odds, recorded at PHOENIX DEER VALLEY MUNI AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 2 | Feb 1 | Jan 1 | Nov 25 | Dec 11 | Dec 29 |
| 32°F | Feb 12 | Jan 8 | Dec 16 | Dec 5 | Dec 25 | Jan 23 |
| 28°F | Feb 2 | Jan 8 | Dec 15 | Dec 14 | Jan 7 | 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 Phoenix, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 18 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.
Phoenix planting FAQ
When is the last spring frost in Phoenix, AZ?
Phoenix's average last spring frost falls near January 8 — 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 Phoenix, AZ?
In Phoenix, the first 32°F freeze of fall lands around December 25 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Phoenix in?
Phoenix is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Phoenix?
Phoenix has about 351 frost-free days — a long growing season — between the average last spring frost (January 8) and first fall frost (December 25).
When should I plant tomatoes in Phoenix?
For Phoenix, sow tomatoes indoors about November 13–November 27 and move the seedlings out around January 15, after the last spring frost.
Never miss a window in Phoenix
An email when it’s time to start seeds, transplant, and sow — timed to Phoenix’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Glendale · 10 km
- Paradise Valley · 12 km
- Sun City · 19 km
- El Mirage · 22 km
- Scottsdale · 25 km
- Tempe · 25 km
- Sun City West · 27 km
- Anthem · 31 km
Frost dates recorded at PHOENIX DEER VALLEY MUNI AP, 13 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 Phoenix, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00003184. Retrieved from https://blissgarden.com/arizona/phoenix.