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When to plant in Santa Ana, CA

USDA Zone 10b

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

Santa Ana enjoys a long ~354-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. Zone 10b is warm enough that Santa Ana can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · TUSTIN IRVINE RCH · 12.5 km
Last spring frost
January 5
50% chance · 32°F
First fall frost
December 25
50% chance · 32°F
Growing season
354 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for Santa AnaA year-band showing 32°F frost risk from January to December for Santa Ana: last spring frost around January 5, first fall frost around December 25, about 354 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

TUSTIN IRVINE RCH · 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 Santa Ana’s own odds, recorded at TUSTIN IRVINE RCH.

Frost-probability curves for Santa AnaProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 5 and the first fall frost around December 25, giving about 354 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 5Feb 1Jan 3Nov 24Dec 13Jan 8
32°FFeb 2Jan 5Dec 14Dec 3Dec 25Jan 20

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

Nearby weather stations

3 within 35 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.

TUSTIN IRVINE RCH
Primary
13 km · 72 m elevation
SPRING
Jan 5
FALL
Dec 25
LAGUNA BEACH
23 km · 13 m elevation
SPRING
Jan 6
FALL
Jan 2
CHINO AP
35 km · 198 m elevation
SPRING
Jan 17
FALL
Dec 19

Santa Ana planting FAQ

When is the last spring frost in Santa Ana, CA?

On average, the last spring frost in Santa Ana is around January 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 Santa Ana, CA?

In Santa Ana, 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 Santa Ana in?

Santa Ana is in USDA hardiness zone 10b. In zone 10b, winters are mild — many tender perennials overwinter here.

How long is the growing season in Santa Ana?

There are roughly 354 frost-free days in Santa Ana (a long growing season), running from the average last frost around January 5 to the first fall frost near December 25.

When should I plant tomatoes in Santa Ana?

In Santa Ana, start tomato seeds indoors around November 10–November 24, then transplant seedlings outdoors around January 12 once the danger of frost has passed.

Planting reminders

Never miss a window in Santa Ana

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

Nearby cities

8 within reach

Frost dates recorded at TUSTIN IRVINE RCH, 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 Santa Ana, CA — Frost Dates & Zone 10b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00049087. Retrieved from https://blissgarden.com/california/santa-ana.
When to Plant in Santa Ana, CA — Frost Dates & Zone 10b — BlissGarden