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When to plant in Oakley, CA

USDA Zone 9b

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

Oakley enjoys a long ~341-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 Oakley can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · ANTIOCH PUMPING PLT #3 · 5.4 km
Last spring frost
January 12
50% chance · 32°F
First fall frost
December 19
50% chance · 32°F
Growing season
341 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for OakleyA year-band showing 32°F frost risk from January to December for Oakley: last spring frost around January 12, first fall frost around December 19, about 341 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average last spring frost in Oakley is now 15 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

ANTIOCH PUMPING PLT #3 · 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 Oakley’s own odds, recorded at ANTIOCH PUMPING PLT #3.

Frost-probability curves for OakleyProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 12 and the first fall frost around December 19, giving about 341 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 12Feb 8Jan 11Nov 18Dec 4Dec 28
32°FFeb 1Jan 12Dec 20Nov 29Dec 19Jan 12
28°FJan 22Jan 2Dec 16Dec 9Dec 29Jan 16

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

Nearby weather stations

3 within 24 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.

ANTIOCH PUMPING PLT #3
Primary
5 km · 18 m elevation
SPRING
Jan 12
FALL
Dec 19
TRACY PUMPING PLT
24 km · 19 m elevation
SPRING
Jan 19
FALL
Dec 10
MT DIABLO JUNCTION
24 km · 661 m elevation
SPRING
Mar 8
FALL
Dec 22

Oakley planting FAQ

When is the last spring frost in Oakley, CA?

Oakley's average last spring frost falls near January 12 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.

When is the first fall frost in Oakley, CA?

In Oakley, 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 Oakley in?

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

How long is the growing season in Oakley?

There are roughly 341 frost-free days in Oakley (a long growing season), running from the average last frost around January 12 to the first fall frost near December 19.

When should I plant tomatoes in Oakley?

In Oakley, start tomato seeds indoors around November 17–December 1, then transplant seedlings outdoors around January 19 once the danger of frost has passed.

Planting reminders

Never miss a window in Oakley

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

Nearby cities

8 within reach

Frost dates recorded at ANTIOCH PUMPING PLT #3, 5 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 Oakley, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00040232. Retrieved from https://blissgarden.com/california/oakley.
When to Plant in Oakley, CA — Frost Dates & Zone 9b — BlissGarden