When to plant in Fountain Hills, AZ
USDA Zone 9bFountain Hills, Arizona frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Fountain Hills enjoys a long ~356-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 Fountain Hills — most perennials thrive, and annual vegetables can go out early and stay late.
The average last spring frost in Fountain Hills is now 12 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
FOUNTAIN HILLS · 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 Fountain Hills’s own odds, recorded at FOUNTAIN HILLS.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 1 | Jan 31 | Dec 31 | Nov 25 | Dec 14 | Jan 3 |
| 32°F | Feb 11 | Jan 6 | Dec 14 | Dec 4 | Dec 28 | Jan 27 |
| 28°F | Jan 31 | Jan 9 | Dec 27 | Dec 26 | Jan 8 | Jan 31 |
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 Fountain Hills, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 17 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.
Fountain Hills planting FAQ
When is the last spring frost in Fountain Hills, AZ?
Plan for the last spring frost in Fountain Hills around January 6 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Fountain Hills, AZ?
In Fountain Hills, the first 32°F freeze of fall lands around December 28 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Fountain Hills in?
Fountain Hills is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Fountain Hills?
Fountain Hills has about 356 frost-free days — a long growing season — between the average last spring frost (January 6) and first fall frost (December 28).
When should I plant tomatoes in Fountain Hills?
For Fountain Hills, sow tomatoes indoors about November 11–November 25 and move the seedlings out around January 13, after the last spring frost.
Never miss a window in Fountain Hills
An email when it’s time to start seeds, transplant, and sow — timed to Fountain Hills’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Scottsdale · 14 km
- Paradise Valley · 22 km
- Mesa · 23 km
- Tempe · 30 km
- Apache Junction · 31 km
- Phoenix · 33 km
- Gilbert · 33 km
- Chandler · 38 km
Frost dates recorded at FOUNTAIN HILLS, 2 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 Fountain Hills, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00023190. Retrieved from https://blissgarden.com/arizona/fountain-hills.