When to plant in Surprise, AZ
USDA Zone 9bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Surprise, Arizona — all computed from Surprise's nearest NOAA weather station.
Surprise enjoys a long ~309-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 Surprise — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
WITTMANN 1SE · 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 Surprise’s own odds, recorded at WITTMANN 1SE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 2 | Mar 4 | Feb 6 | Nov 8 | Nov 26 | Dec 14 |
| 32°F | Mar 3 | Feb 5 | Jan 6 | Nov 20 | Dec 11 | Jan 2 |
| 28°F | Feb 12 | Jan 15 | Dec 14 | Dec 4 | Dec 27 | Jan 28 |
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 Surprise, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 21 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.
Surprise planting FAQ
When is the last spring frost in Surprise, AZ?
On average, the last spring frost in Surprise is around February 5 (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 Surprise, AZ?
Expect Surprise's first fall frost near December 11 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Surprise in?
Surprise is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Surprise?
Surprise has about 309 frost-free days — a long growing season — between the average last spring frost (February 5) and first fall frost (December 11).
When should I plant tomatoes in Surprise?
For Surprise, 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 Surprise
An email when it’s time to start seeds, transplant, and sow — timed to Surprise’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at WITTMANN 1SE, 14 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 Surprise, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00029464. Retrieved from https://blissgarden.com/arizona/surprise.