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When to plant in Spring Valley, CA

USDA Zone 10b

Spring Valley, California frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.

Spring Valley enjoys a long ~349-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 Spring Valley can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · EL CAJON · 9.1 km
Last spring frost
January 6
50% chance · 32°F
First fall frost
December 21
50% chance · 32°F
Growing season
349 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for Spring ValleyA year-band showing 32°F frost risk from January to December for Spring Valley: last spring frost around January 6, first fall frost around December 21, about 349 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average last spring frost in Spring Valley is now 6 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

EL CAJON · 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 Spring Valley’s own odds, recorded at EL CAJON.

Frost-probability curves for Spring ValleyProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 6 and the first fall frost around December 21, giving about 349 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 3Feb 6Jan 6Nov 18Dec 6Dec 29
32°FFeb 7Jan 6Dec 13Dec 1Dec 21Jan 15
28°FJan 15Dec 31Dec 8Dec 7Dec 30Jan 14

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

Nearby weather stations

3 within 22 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.

EL CAJON
Primary
9 km · 151 m elevation
SPRING
Jan 6
FALL
Dec 21
SAN DIEGO BROWN FLD
18 km · 157 m elevation
SPRING
Jan 6
FALL
Dec 31
ALPINE
22 km · 517 m elevation
SPRING
Feb 12
FALL
Dec 24

Spring Valley planting FAQ

When is the last spring frost in Spring Valley, CA?

On average, the last spring frost in Spring Valley is around January 6 (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 Spring Valley, CA?

Expect Spring Valley's first fall frost near December 21 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is Spring Valley in?

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

How long is the growing season in Spring Valley?

There are roughly 349 frost-free days in Spring Valley (a long growing season), running from the average last frost around January 6 to the first fall frost near December 21.

When should I plant tomatoes in Spring Valley?

In Spring Valley, start tomato seeds indoors around November 11–November 25, then transplant seedlings outdoors around January 13 once the danger of frost has passed.

Planting reminders

Never miss a window in Spring Valley

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

Nearby cities

8 within reach

Frost dates recorded at EL CAJON, 9 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 Spring Valley, CA — Frost Dates & Zone 10b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00042706. Retrieved from https://blissgarden.com/california/spring-valley.
When to Plant in Spring Valley, CA — Frost Dates & Zone 10b — BlissGarden