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When to plant in San Jacinto, CA

USDA Zone 9b

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

San Jacinto enjoys a long ~313-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. Zone 9b is warm enough that San Jacinto can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · SAN JACINTO · 1.9 km
Last spring frost
January 31
50% chance · 32°F
First fall frost
December 10
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 San JacintoA year-band showing 32°F frost risk from January to December for San Jacinto: last spring frost around January 31, first fall frost around December 10, about 313 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average last spring frost in San Jacinto is now 26 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

SAN JACINTO · 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 San Jacinto’s own odds, recorded at SAN JACINTO.

Frost-probability curves for San JacintoProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 31 and the first fall frost around December 10, 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°FApr 8Mar 5Feb 6Nov 5Nov 24Dec 12
32°FFeb 28Jan 31Dec 31Nov 22Dec 10Jan 6
28°FJan 29Jan 3Dec 11Dec 2Dec 21Jan 15

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

Nearby weather stations

3 within 27 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.

SAN JACINTO
Primary
2 km · 465 m elevation
SPRING
Jan 31
FALL
Dec 10
HEMET
12 km · 552 m elevation
SPRING
Jan 10
FALL
Dec 23
IDYLLWILD FIRE DEPT
27 km · 1640 m elevation
SPRING
May 16
FALL
Oct 24

San Jacinto planting FAQ

When is the last spring frost in San Jacinto, CA?

Plan for the last spring frost in San Jacinto around January 31 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.

When is the first fall frost in San Jacinto, CA?

In San Jacinto, the first 32°F freeze of fall lands around December 10 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is San Jacinto in?

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

How long is the growing season in San Jacinto?

There are roughly 313 frost-free days in San Jacinto (a long growing season), running from the average last frost around January 31 to the first fall frost near December 10.

When should I plant tomatoes in San Jacinto?

In San Jacinto, start tomato seeds indoors around December 6–December 20, then transplant seedlings outdoors around February 7 once the danger of frost has passed.

Planting reminders

Never miss a window in San Jacinto

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

Nearby cities

8 within reach

Frost dates recorded at SAN JACINTO, 2 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 San Jacinto, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00047813. Retrieved from https://blissgarden.com/california/san-jacinto.