Discovery Bay, CA frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 10 a year). Cover tender plants when frost is forecast.
How Discovery Bay compares
- In a typical year, frost nights in Discovery Bay fall between December 10 and January 19. In 1 year in 10 the first frost comes as early as November 26, or the last frost as late as February 17.
- Compared with Brentwood, CA, 8 km away, the last frost here is 7 days later than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 25 |
| 50% (median) | January 19 |
| 10% (safe for tender plants) | February 17 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 26 |
| 50% (median) | December 10 |
| 90% (late) | January 7 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Gardening where frost is rare
Discovery Bay, CA only freezes on a few winter nights, so the usual "plant after the last frost" rule doesn't apply. Heat and rainfall decide the seasons instead:
- Cool-season crops (lettuce, broccoli, peas, carrots) grow best from fall through late winter.
- Warm-season crops (tomatoes, peppers, beans, squash) do best planted in late winter to spring, and again in late summer for a fall crop — midsummer heat can stop tomatoes setting fruit.
- Heat lovers (okra, sweet potatoes, melons) can be planted through spring and early summer.
About these dates
Based on 1991–2020 NOAA climate normals for the Tracy Pumping Plt, CA weather station, 12 km away (elevation 62 ft (19 m)).
Frost dates near Discovery Bay
- Brentwood Jan 12 · Dec 19
- Byron Jan 19 · Dec 10
- Knightsen Jan 12 · Dec 19
- Oakley Jan 12 · Dec 19
- Bethel Island Jan 12 · Dec 19
- Holt Feb 5 · Dec 8
- Antioch Jan 12 · Dec 19
- Tracy Feb 25 · Nov 26
- Livermore Feb 15 · Dec 2
- Clayton Mar 8 · Dec 22
Frequently asked questions
When is the last frost in Discovery Bay, CA?
The median last spring frost in Discovery Bay, CA is January 19. There is still about a 10% chance of frost after February 17, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Discovery Bay, CA?
The median first fall frost is December 10, with about a 10% chance of frost before November 26.
How long is the growing season in Discovery Bay, CA?
About 325 days between the median last spring frost and first fall frost.
What planting zone is Discovery Bay, CA?
Discovery Bay, CA is in USDA hardiness zone 9b.