When to plant in Danville, CA
USDA Zone 9bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Danville, California — all computed from Danville's nearest NOAA weather station.
With about 289 frost-free days, Danville supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Zone 9b is warm enough that Danville can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
MT DIABLO JUNCTION · 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 Danville’s own odds, recorded at MT DIABLO JUNCTION.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 20 | Apr 19 | Mar 16 | Nov 6 | Nov 29 | Dec 20 |
| 32°F | Apr 15 | Mar 8 | Jan 12 | Nov 23 | Dec 22 | Feb 11 |
| 28°F | Mar 23 | Feb 8 | Dec 21 | Dec 8 | Jan 16 | Mar 3 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in Danville, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 19 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.
Danville planting FAQ
When is the last spring frost in Danville, CA?
Plan for the last spring frost in Danville around March 8 (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 Danville, CA?
The first fall frost in Danville typically arrives around December 22 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Danville in?
Danville is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Danville?
There are roughly 289 frost-free days in Danville (a long growing season), running from the average last frost around March 8 to the first fall frost near December 22.
When should I plant tomatoes in Danville?
In Danville, start tomato seeds indoors around January 11–January 25, then transplant seedlings outdoors around March 15 once the danger of frost has passed.
Never miss a window in Danville
An email when it’s time to start seeds, transplant, and sow — timed to Danville’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Blackhawk · 5 km
- Alamo · 6 km
- San Ramon · 6 km
- Walnut Creek · 12 km
- Dublin · 12 km
- Moraga · 14 km
- Castro Valley · 14 km
- Clayton · 15 km
Frost dates recorded at MT DIABLO JUNCTION, 8 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 Danville, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00045915. Retrieved from https://blissgarden.com/california/danville.