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When to plant in Gilbert, AZ

USDA Zone 9b

Everything below — frost dates, hardiness zone, and what to plant when in Gilbert, Arizona — is derived from the closest NOAA station with complete climate normals.

A generous ~313-day season lets Gilbert gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9b is warm enough that Gilbert can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · CHANDLER HEIGHTS · 12.9 km
Last spring frost
February 1
50% chance · 32°F
First fall frost
December 11
50% chance · 32°F
Growing season
313 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for GilbertA year-band showing 32°F frost risk from January to December for Gilbert: last spring frost around February 1, first fall frost around December 11, about 313 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

CHANDLER HEIGHTS · 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 Gilbert’s own odds, recorded at CHANDLER HEIGHTS.

Frost-probability curves for GilbertProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around February 1 and the first fall frost around December 11, giving about 313 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 11Feb 21Jan 29Nov 12Nov 28Dec 14
32°FFeb 27Feb 1Jan 2Nov 23Dec 11Jan 1
28°FFeb 11Jan 8Dec 15Dec 4Dec 26Jan 29

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 Gilbert, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 21 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.

CHANDLER HEIGHTS
Primary
13 km · 434 m elevation
SPRING
Feb 1
FALL
Dec 11
E MESA
15 km · 463 m elevation
SPRING
Feb 1
FALL
Dec 10
TEMPE ASU
21 km · 356 m elevation
SPRING
Feb 13
FALL
Dec 5

Gilbert planting FAQ

When is the last spring frost in Gilbert, AZ?

On average, the last spring frost in Gilbert is around February 1 (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 Gilbert, AZ?

In Gilbert, the first 32°F freeze of fall lands around December 11 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is Gilbert in?

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

How long is the growing season in Gilbert?

There are roughly 313 frost-free days in Gilbert (a long growing season), running from the average last frost around February 1 to the first fall frost near December 11.

When should I plant tomatoes in Gilbert?

In Gilbert, start tomato seeds indoors around December 7–December 21, then transplant seedlings outdoors around February 8 once the danger of frost has passed.

Planting reminders

Never miss a window in Gilbert

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

Nearby cities

8 within reach

Frost dates recorded at CHANDLER HEIGHTS, 13 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 Gilbert, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00021514. Retrieved from https://blissgarden.com/arizona/gilbert.
When to Plant in Gilbert, AZ — Frost Dates & Zone 9b — BlissGarden