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When to plant in Rio Vista, CA

USDA Zone 9b

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

Rio Vista 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. Heads up: the nearest complete-normals station is about 22 km from Rio Vista, so your yard's frost dates can differ — a low spot or a paved city center can shift them by a week. Zone 9b is warm enough that Rio Vista can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · ANTIOCH PUMPING PLT #3 · 21.9 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 Rio VistaA year-band showing 32°F frost risk from January to December for Rio Vista: 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 Rio Vista 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 Rio Vista’s own odds, recorded at ANTIOCH PUMPING PLT #3.

Frost-probability curves for Rio VistaProbability 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 Rio Vista, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 33 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
22 km · 18 m elevation
SPRING
Jan 12
FALL
Dec 19
VACAVILLE NUT TREE AP
31 km · 33 m elevation
SPRING
Feb 18
FALL
Nov 28
VACAVILLE
33 km · 34 m elevation
SPRING
Jan 31
FALL
Dec 11

Rio Vista planting FAQ

When is the last spring frost in Rio Vista, CA?

Rio Vista'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 Rio Vista, CA?

Expect Rio Vista's first fall frost near December 19 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is Rio Vista in?

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

How long is the growing season in Rio Vista?

There are roughly 341 frost-free days in Rio Vista (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 Rio Vista?

In Rio Vista, 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 Rio Vista

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

Nearby cities

8 within reach

Frost dates recorded at ANTIOCH PUMPING PLT #3, 22 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 Rio Vista, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00040232. Retrieved from https://blissgarden.com/california/rio-vista.
When to Plant in Rio Vista, CA — Frost Dates & Zone 9b — BlissGarden