blissgarden.

When to plant in Concord, CA

USDA Zone 9b

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

Concord enjoys a long ~339-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 Concord can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · CONCORD BUCHANAN FLD · 5.2 km
Last spring frost
January 9
50% chance · 32°F
First fall frost
December 14
50% chance · 32°F
Growing season
339 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for ConcordA year-band showing 32°F frost risk from January to December for Concord: last spring frost around January 9, first fall frost around December 14, about 339 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average last spring frost in Concord is now 13 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

CONCORD BUCHANAN FLD · 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 Concord’s own odds, recorded at CONCORD BUCHANAN FLD.

Frost-probability curves for ConcordProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 9 and the first fall frost around December 14, giving about 339 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 13Feb 14Jan 12Nov 14Dec 1Dec 26
32°FFeb 12Jan 9Dec 16Nov 28Dec 14Jan 16
28°FJan 19Dec 30Dec 10Dec 5Dec 23Jan 12

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

Nearby weather stations

3 within 11 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.

CONCORD BUCHANAN FLD
Primary
5 km · 6 m elevation
SPRING
Jan 9
FALL
Dec 14
CONCORD WWTP
6 km · 12 m elevation
SPRING
Jan 7
FALL
Dec 19
MARTINEZ WTP
11 km · 12 m elevation
SPRING
Feb 28
FALL
Nov 22

Concord planting FAQ

When is the last spring frost in Concord, CA?

Plan for the last spring frost in Concord around January 9 (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 Concord, CA?

The first fall frost in Concord typically arrives around December 14 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.

What hardiness zone is Concord in?

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

How long is the growing season in Concord?

There are roughly 339 frost-free days in Concord (a long growing season), running from the average last frost around January 9 to the first fall frost near December 14.

When should I plant tomatoes in Concord?

In Concord, start tomato seeds indoors around November 14–November 28, then transplant seedlings outdoors around January 16 once the danger of frost has passed.

Planting reminders

Never miss a window in Concord

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

Nearby cities

8 within reach

Frost dates recorded at CONCORD BUCHANAN FLD, 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 Concord, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00023254. Retrieved from https://blissgarden.com/california/concord.
When to Plant in Concord, CA — Frost Dates & Zone 9b — BlissGarden