When to plant in Vacaville, CA
USDA Zone 9bEverything below — frost dates, hardiness zone, and what to plant when in Vacaville, California — is derived from the closest NOAA station with complete climate normals.
A generous ~283-day season lets Vacaville gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9b is warm enough that Vacaville can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average first fall frost in Vacaville is now 8 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
VACAVILLE NUT TREE AP · 1991–2020The 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 Vacaville’s own odds, recorded at VACAVILLE NUT TREE AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 19 | Mar 28 | Feb 26 | Nov 1 | Nov 13 | Nov 30 |
| 32°F | Mar 25 | Feb 18 | Jan 11 | Nov 12 | Nov 28 | Dec 18 |
| 28°F | Feb 17 | Jan 15 | Dec 21 | Nov 24 | Dec 10 | Jan 11 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Vacaville, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 13 km · complete 32°F normalsWhen 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.
Vacaville planting FAQ
When is the last spring frost in Vacaville, CA?
Vacaville's average last spring frost falls near February 18 — 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 Vacaville, CA?
Expect Vacaville's first fall frost near November 28 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Vacaville in?
Vacaville is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Vacaville?
There are roughly 283 frost-free days in Vacaville (a long growing season), running from the average last frost around February 18 to the first fall frost near November 28.
When should I plant tomatoes in Vacaville?
In Vacaville, start tomato seeds indoors around December 24–January 7, then transplant seedlings outdoors around February 25 once the danger of frost has passed.
Never miss a window in Vacaville
An email when it’s time to start seeds, transplant, and sow — timed to Vacaville’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Fairfield · 12 km
- Suisun City · 13 km
- Dixon · 16 km
- Napa · 30 km
- Davis · 30 km
- Rio Vista · 31 km
- American Canyon · 32 km
- Benicia · 36 km
Frost dates recorded at VACAVILLE NUT TREE AP, 2 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Vacaville, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00093241. Retrieved from https://blissgarden.com/california/vacaville.