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When to plant in San Jose, CA

USDA Zone 9b

Everything below — frost dates, hardiness zone, and what to plant when in San Jose, California — is derived from the closest NOAA station with complete climate normals.

San Jose enjoys a long ~357-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. In zone 9b, frost is a minor factor for San Jose — most perennials thrive, and annual vegetables can go out early and stay late.

Station · SAN JOSE · 9.9 km
Last spring frost
January 2
50% chance · 32°F
First fall frost
December 25
50% chance · 32°F
Growing season
357 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for San JoseA year-band showing 32°F frost risk from January to December for San Jose: last spring frost around January 2, first fall frost around December 25, about 357 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average last spring frost in San Jose is now 11 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

SAN JOSE · 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 Jose’s own odds, recorded at SAN JOSE.

Frost-probability curves for San JoseProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 2 and the first fall frost around December 25, giving about 357 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°FFeb 27Jan 26Dec 27Nov 22Dec 10Jan 4
32°FJan 23Jan 2Dec 14Dec 4Dec 25Jan 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 San Jose, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 15 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.

SAN JOSE
Primary
10 km · 20 m elevation
SPRING
Jan 2
FALL
Dec 25
SAN JOSE
12 km · 16 m elevation
SPRING
Jan 12
FALL
Dec 22
LOS GATOS
15 km · 111 m elevation
SPRING
Feb 2
FALL
Dec 6

San Jose planting FAQ

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

Plan for the last spring frost in San Jose around January 2 (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 San Jose, CA?

In San Jose, the first 32°F freeze of fall lands around December 25 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is San Jose in?

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

How long is the growing season in San Jose?

San Jose has about 357 frost-free days — a long growing season — between the average last spring frost (January 2) and first fall frost (December 25).

When should I plant tomatoes in San Jose?

For San Jose, sow tomatoes indoors about November 7–November 21 and move the seedlings out around January 9, after the last spring frost.

Planting reminders

Never miss a window in San Jose

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

Nearby cities

8 within reach

Frost dates recorded at SAN JOSE, 10 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 Jose, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00047821. Retrieved from https://blissgarden.com/california/san-jose.
When to Plant in San Jose, CA — Frost Dates & Zone 9b — BlissGarden