When to plant in Campbell, CA
USDA Zone 9bEverything below — frost dates, hardiness zone, and what to plant when in Campbell, California — is derived from the closest NOAA station with complete climate normals.
Campbell enjoys a long ~307-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 Campbell can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Campbell is now 12 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
LOS GATOS · 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 Campbell’s own odds, recorded at LOS GATOS.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 16 | Mar 20 | Feb 16 | Nov 4 | Nov 20 | Dec 5 |
| 32°F | Mar 14 | Feb 2 | Dec 31 | Nov 16 | Dec 6 | Jan 7 |
| 28°F | Jan 26 | Jan 1 | Dec 9 | Nov 28 | Dec 19 | Jan 13 |
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 Campbell, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 9 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.
Campbell planting FAQ
When is the last spring frost in Campbell, CA?
On average, the last spring frost in Campbell is around February 2 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Campbell, CA?
Expect Campbell's first fall frost near December 6 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Campbell in?
Campbell is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Campbell?
There are roughly 307 frost-free days in Campbell (a long growing season), running from the average last frost around February 2 to the first fall frost near December 6.
When should I plant tomatoes in Campbell?
In Campbell, start tomato seeds indoors around December 8–December 22, then transplant seedlings outdoors around February 9 once the danger of frost has passed.
Never miss a window in Campbell
An email when it’s time to start seeds, transplant, and sow — timed to Campbell’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at LOS GATOS, 5 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 Campbell, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00045123. Retrieved from https://blissgarden.com/california/campbell.