When to plant in Discovery Bay, CA
USDA Zone 9bEverything below — frost dates, hardiness zone, and what to plant when in Discovery Bay, California — is derived from the closest NOAA station with complete climate normals.
A generous ~325-day season lets Discovery Bay gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9b is warm enough that Discovery Bay can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Discovery Bay is now 11 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
TRACY PUMPING PLT · 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 Discovery Bay’s own odds, recorded at TRACY PUMPING PLT.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 24 | Feb 21 | Jan 22 | Nov 13 | Nov 29 | Dec 13 |
| 32°F | Feb 17 | Jan 19 | Dec 25 | Nov 26 | Dec 10 | Jan 7 |
| 28°F | Jan 22 | Jan 1 | Dec 12 | Dec 4 | Dec 22 | Jan 10 |
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 Discovery Bay, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 27 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.
Discovery Bay planting FAQ
When is the last spring frost in Discovery Bay, CA?
On average, the last spring frost in Discovery Bay is around January 19 (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 Discovery Bay, CA?
In Discovery Bay, the first 32°F freeze of fall lands around December 10 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Discovery Bay in?
Discovery Bay is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Discovery Bay?
There are roughly 325 frost-free days in Discovery Bay (a long growing season), running from the average last frost around January 19 to the first fall frost near December 10.
When should I plant tomatoes in Discovery Bay?
In Discovery Bay, start tomato seeds indoors around November 24–December 8, then transplant seedlings outdoors around January 26 once the danger of frost has passed.
Never miss a window in Discovery Bay
An email when it’s time to start seeds, transplant, and sow — timed to Discovery Bay’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Brentwood · 11 km
- Oakley · 13 km
- Mountain House · 15 km
- Antioch · 19 km
- Country Club · 23 km
- Tracy · 24 km
- Stockton · 26 km
- Lathrop · 27 km
Frost dates recorded at TRACY PUMPING PLT, 13 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 Discovery Bay, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00049001. Retrieved from https://blissgarden.com/california/discovery-bay.