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When to plant in Sun City, AZ

USDA Zone 9b

Here are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Sun City, Arizona — all computed from Sun City's nearest NOAA weather station.

A generous ~329-day season lets Sun City gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. In zone 9b, frost is a minor factor for Sun City — most perennials thrive, and annual vegetables can go out early and stay late.

Station · YOUNGTOWN · 2.8 km
Last spring frost
January 20
50% chance · 32°F
First fall frost
December 15
50% chance · 32°F
Growing season
329 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for Sun CityA year-band showing 32°F frost risk from January to December for Sun City: last spring frost around January 20, first fall frost around December 15, about 329 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average last spring frost in Sun City is now 7 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

YOUNGTOWN · 1991–2020

The 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 Sun City’s own odds, recorded at YOUNGTOWN.

Frost-probability curves for Sun CityProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 20 and the first fall frost around December 15, giving about 329 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMar 4Feb 14Jan 21Nov 17Dec 2Dec 18
32°FFeb 18Jan 20Dec 23Nov 28Dec 15Jan 7
28°FFeb 1Jan 3Dec 13Dec 10Dec 29Jan 22

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19

Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.

Add the next planting windows to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Sun City, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 20 km · complete 32°F normals

When 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.

YOUNGTOWN
Primary
3 km · 346 m elevation
SPRING
Jan 20
FALL
Dec 15
LITCHFIELD PARK
15 km · 317 m elevation
SPRING
Jan 7
FALL
Dec 24
PHOENIX DEER VALLEY MUNI AP
20 km · 444 m elevation
SPRING
Jan 8
FALL
Dec 25

Sun City planting FAQ

When is the last spring frost in Sun City, AZ?

On average, the last spring frost in Sun City is around January 20 (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 Sun City, AZ?

The first fall frost in Sun City typically arrives around December 15 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.

What hardiness zone is Sun City in?

Sun City is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.

How long is the growing season in Sun City?

Sun City has about 329 frost-free days — a long growing season — between the average last spring frost (January 20) and first fall frost (December 15).

When should I plant tomatoes in Sun City?

For Sun City, sow tomatoes indoors about November 25–December 9 and move the seedlings out around January 27, after the last spring frost.

Planting reminders

Never miss a window in Sun City

An email when it’s time to start seeds, transplant, and sow — timed to Sun City’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at YOUNGTOWN, 3 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Sun City, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00029634. Retrieved from https://blissgarden.com/arizona/sun-city.
When to Plant in Sun City, AZ — Frost Dates & Zone 9b — BlissGarden