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When to plant in Bloomington, CA

USDA Zone 10a

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

With only about -8 frost-free days, Bloomington has a short season — start heat-lovers indoors early, favor quick-maturing varieties, and use row cover to stretch both ends. Zone 10a is warm enough that Bloomington can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · RIVERSIDE CITRUS EXP · 11.0 km
Last spring frost
January 10
50% chance · 32°F
First fall frost
January 2
50% chance · 32°F
Growing season
-8 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for BloomingtonA year-band from January to December for Bloomington: Bloomington is effectively frost-free at 32°F — no distinct frost season.
Bloomington is effectively frost-free at 32°F — no distinct frost season.

The average first fall frost in Bloomington is now 10 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

RIVERSIDE CITRUS EXP · 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 Bloomington’s own odds, recorded at RIVERSIDE CITRUS EXP.

Frost-probability curves for BloomingtonProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 10 and the first fall frost around January 2, where a 32°F freeze is rare enough that there is effectively no distinct frost season.
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 12Feb 11Jan 1Nov 25Dec 13Jan 8
32°FFeb 17Jan 10Dec 20Dec 11Jan 2Feb 7

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

Nearby weather stations

3 within 13 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.

RIVERSIDE CITRUS EXP
Primary
11 km · 301 m elevation
SPRING
Jan 10
FALL
Jan 2
RIVERSIDE FIRE STN 3
12 km · 256 m elevation
SPRING
Jan 9
FALL
Dec 25
RIVERSIDE MUNI AP
13 km · 245 m elevation
SPRING
Jan 9
FALL
Dec 30

Bloomington planting FAQ

When is the last spring frost in Bloomington, CA?

Plan for the last spring frost in Bloomington around January 10 (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 Bloomington, CA?

Expect Bloomington's first fall frost near January 2 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is Bloomington in?

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

How long is the growing season in Bloomington?

There are roughly -8 frost-free days in Bloomington (a short growing season), running from the average last frost around January 10 to the first fall frost near January 2.

When should I plant tomatoes in Bloomington?

In Bloomington, start tomato seeds indoors around November 15–November 29, then transplant seedlings outdoors around January 17 once the danger of frost has passed.

Planting reminders

Never miss a window in Bloomington

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

Nearby cities

8 within reach

Frost dates recorded at RIVERSIDE CITRUS EXP, 11 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 Bloomington, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00047473. Retrieved from https://blissgarden.com/california/bloomington.
When to Plant in Bloomington, CA — Frost Dates & Zone 10a — BlissGarden