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When to plant in San Bernardino, CA

USDA Zone 10a

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

A generous ~326-day season lets San Bernardino gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 10a is warm enough that San Bernardino can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · REDLANDS · 14.8 km
Last spring frost
January 27
50% chance · 32°F
First fall frost
December 19
50% chance · 32°F
Growing season
326 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for San BernardinoA year-band showing 32°F frost risk from January to December for San Bernardino: last spring frost around January 27, first fall frost around December 19, about 326 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

REDLANDS · 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 Bernardino’s own odds, recorded at REDLANDS.

Frost-probability curves for San BernardinoProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 27 and the first fall frost around December 19, giving about 326 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 5Mar 2Jan 31Nov 17Dec 2Dec 19
32°FFeb 28Jan 27Dec 21Dec 1Dec 19Jan 26
28°FFeb 15Jan 7Dec 17Dec 13Jan 1Feb 13

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

Nearby weather stations

3 within 20 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.

REDLANDS
Primary
15 km · 430 m elevation
SPRING
Jan 27
FALL
Dec 19
LAKE ARROWHEAD
15 km · 1587 m elevation
SPRING
May 5
FALL
Nov 2
RIVERSIDE CITRUS EXP
20 km · 301 m elevation
SPRING
Jan 10
FALL
Jan 2

San Bernardino planting FAQ

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

On average, the last spring frost in San Bernardino is around January 27 (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 San Bernardino, CA?

In San Bernardino, the first 32°F freeze of fall lands around December 19 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is San Bernardino in?

San Bernardino is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.

How long is the growing season in San Bernardino?

There are roughly 326 frost-free days in San Bernardino (a long growing season), running from the average last frost around January 27 to the first fall frost near December 19.

When should I plant tomatoes in San Bernardino?

In San Bernardino, start tomato seeds indoors around December 2–December 16, then transplant seedlings outdoors around February 3 once the danger of frost has passed.

Planting reminders

Never miss a window in San Bernardino

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

Nearby cities

8 within reach

Frost dates recorded at REDLANDS, 15 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 Bernardino, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00047306. Retrieved from https://blissgarden.com/california/san-bernardino.
When to Plant in San Bernardino, CA — Frost Dates & Zone 10a — BlissGarden