blissgarden.

When to plant in Anthem, AZ

USDA Zone 9b

Anthem, 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, Anthem supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. These dates come from a station roughly 18 km away, the closest with full normals; terrain around Anthem (elevation, water, pavement) can move your real frost dates a few days either way. Zone 9b is warm enough that Anthem can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · PHOENIX DEER VALLEY MUNI AP · 18.1 km
Last spring frost
January 8
50% chance · 32°F
First fall frost
December 25
50% chance · 32°F
Growing season
351 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for AnthemA year-band showing 32°F frost risk from January to December for Anthem: last spring frost around January 8, first fall frost around December 25, about 351 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

PHOENIX DEER VALLEY MUNI AP · 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 Anthem’s own odds, recorded at PHOENIX DEER VALLEY MUNI AP.

Frost-probability curves for AnthemProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 8 and the first fall frost around December 25, giving about 351 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 2Feb 1Jan 1Nov 25Dec 11Dec 29
32°FFeb 12Jan 8Dec 16Dec 5Dec 25Jan 23
28°FFeb 2Jan 8Dec 15Dec 14Jan 7Feb 1

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

Nearby weather stations

3 within 26 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.

PHOENIX DEER VALLEY MUNI AP
Primary
18 km · 444 m elevation
SPRING
Jan 8
FALL
Dec 25
CAREFREE
21 km · 771 m elevation
SPRING
Feb 4
FALL
Dec 16
CASTLE HOT SPRINGS
26 km · 607 m elevation
SPRING
Jan 15
FALL
Dec 22

Anthem planting FAQ

When is the last spring frost in Anthem, AZ?

On average, the last spring frost in Anthem is around January 8 (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 Anthem, AZ?

In Anthem, 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 Anthem in?

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

How long is the growing season in Anthem?

There are roughly 351 frost-free days in Anthem (a long growing season), running from the average last frost around January 8 to the first fall frost near December 25.

When should I plant tomatoes in Anthem?

In Anthem, start tomato seeds indoors around November 13–November 27, then transplant seedlings outdoors around January 15 once the danger of frost has passed.

Planting reminders

Never miss a window in Anthem

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

Nearby cities

8 within reach

Frost dates recorded at PHOENIX DEER VALLEY MUNI AP, 18 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 Anthem, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00003184. Retrieved from https://blissgarden.com/arizona/anthem.