Oakley, CA planting zone & frost dates

Oakley is in USDA hardiness zone 9b. The last spring frost usually comes around January 12 and the first fall frost around December 19, for a growing season of about 343 days.

USDA hardiness zone9bavg. extreme winter low 25°F to 30°F

Average last spring frostJanuary 1290% chance of no frost after February 1

Average first fall frostDecember 1910% chance of frost by November 29

Growing season343 daysfrost-free days in an average year

Planting calendar for Oakley

Dates are counted from the average last spring frost (January 12) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.

Crop	When
Tomatoes	Start seeds indoors: Nov 17 – Dec 1 Transplant outdoors: Jan 19 – Jan 26
Peppers	Start seeds indoors: Nov 3 – Nov 17 Transplant outdoors: Jan 26 – Feb 2
Eggplant	Start seeds indoors: Nov 3 – Nov 17 Transplant outdoors: Jan 26 – Feb 2
Broccoli	Start seeds indoors: Nov 3 – Nov 17 Transplant outdoors: Dec 15 – Dec 29
Cabbage	Start seeds indoors: Nov 3 – Nov 17 Transplant outdoors: Dec 15 – Dec 29
Onions (sets)	Plant outdoors: Dec 15 – Dec 29
Peas	Sow outdoors: Dec 1 – Dec 15
Spinach	Sow outdoors: Dec 1 – Dec 15
Lettuce	Sow outdoors: Dec 15 – Dec 29
Carrots	Sow outdoors: Dec 15 – Dec 29
Potatoes	Plant outdoors: Dec 15 – Dec 29
Beans	Sow outdoors: Jan 19 – Jan 26
Sweet corn	Sow outdoors: Jan 19 – Jan 26
Cucumbers	Sow outdoors: Jan 19 – Jan 26
Squash & zucchini	Sow outdoors: Jan 19 – Jan 26
Basil	Start seeds indoors: Dec 1 – Dec 15 Transplant outdoors: Jan 19 – Jan 26

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 24 (8 weeks before the average first fall frost on Dec 19).

Frost risk in detail

	90% chance	50% chance	10% chance
Last 32°F frost in spring is after	Dec 20	Jan 12	Feb 1
First 32°F frost in fall is before	Jan 12	Dec 19	Nov 29

How to read it: in spring there is a 10% chance of a frost after February 1, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 29. A hard freeze (28°F) usually ends around January 2.

Hardiness zone by ZIP code in Oakley

94561 zone 9b

Nearby cities

Brentwood zone 9b, last frost Jan 12
Antioch zone 9b, last frost Jan 12
Discovery Bay zone 9b, last frost Jan 19
Pittsburg zone 9b, last frost Jan 12
Clayton zone 9b, last frost Jan 9
Bay Point zone 9b, last frost Jan 9
Concord zone 9b, last frost Jan 9
Livermore zone 9b, last frost Feb 15

All cities in California → · Other zone 9b cities →

Questions

What growing zone is Oakley, CA?

Oakley is in USDA Plant Hardiness Zone 9b (average extreme winter low 25°F to 30°F), according to the USDA 2023 map.

When is the last frost in Oakley?

The average last spring frost (32°F) in Oakley is January 12. There is still a 10% chance of frost until February 1.

When can I plant tomatoes in Oakley?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jan 19 – Jan 26. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Antioch Pumping Plt #3, CA (USC00040232), 3.8 km (2.4 mi) from the city center, elevation 18 m, based on 19 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.