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California Last Frost Date 2027

The average last spring frost (32°F, 50% chance) in California falls between Dec 29 in San Mateo County and Jun 11 in Sierra County. The first fall frost comes between Sep 10 (Sierra County) and Jan 7 (Los Angeles County).

Photo: Savoy cabbage head and outer leaves covered in hoar frost in a vegetable garden. Schlaghecken Josef, CC BY-SA 4.0, via Wikimedia Commons

When to plant in California: crop by crop

Planting dates for each crop in California, from the UC Master Gardener Program calendar.

Tomatoes

Peppers

Potatoes

Sweet Corn

Green Beans

Cucumbers

Squash

Lettuce

Onions

Garlic

Peas

Watermelon

California frost date questions

When is the last frost in California?

The average last spring frost (32°F, 50% chance) in California falls between Dec 29 in San Mateo County and Jun 11 in Sierra County. The first fall frost comes between Sep 10 (Sierra County) and Jan 7 (Los Angeles County).

What does a 50% last frost date mean?

In half of the years from 1991 to 2020, the last 32°F night came on or after that date. Waiting until the 10% date cuts the risk to about 1 year in 10.

When is it safe to plant tomatoes in California?

Tender crops such as tomatoes and peppers go out after the last frost. Use the 10% date for your county for a safer margin; the UC Master Gardener Program planting calendar has the crop dates.

When is the first frost in California?

The 50% first fall frost ranges from Sep 10 in Sierra County to Jan 7 in Los Angeles County.

How long is the growing season in California?

Between 91 days (Sierra County) and 365 days (Alameda County) between the last and first 32°F freeze in half of years.

What is the difference between frost and a hard freeze?

These dates use 32°F, when tender plants are damaged. A 28°F hard freeze damages most hardy vegetables; the widget shows both.

Where do these frost dates come from?

NOAA NCEI U.S. Climate Normals for 1991 to 2020, freeze probability dates for each weather station. Each county uses its nearest station with a complete record.

Why does my county use a station in another county?

Not every county has a NOAA station with a full 30-year record. The station name, distance and elevation are listed so you can judge how close it is to your garden.

Photos: Savoy cabbage head and outer leaves covered in hoar frost in a vegetable garden: Schlaghecken Josef, CC BY-SA 4.0, via Wikimedia Commons; Green subalpine meadow and granite dome at Tuolumne Meadows, Yosemite National Park: James St. John, CC BY 2.0, via Wikimedia Commons; Yosemite Valley with the Merced River in the foreground and granite walls behind: King of Hearts, CC BY-SA 3.0, via Wikimedia Commons; Sandy bank of Mirror Lake with granite walls and pines in Yosemite Valley: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons; Snow-covered Mount Shasta above Lake Siskiyou and forested shore: Radomianin, CC BY-SA 4.0, via Wikimedia Commons; Staked tomato plant in a straw-mulched kitchen garden with green and ripening red tomatoes: NPS, Public domain, via Wikimedia Commons; Pepper plant in a kitchen garden loaded with green, yellow and red peppers: NPS, Public domain, via Wikimedia Commons; Long neat rows of green potato plants stretching across a farm field: Malcolm Neal, CC BY-SA 2.0, via Wikimedia Commons; Tall corn plants with golden tassels against a summer sky in a field: inkknife_2000, CC BY-SA 2.0, via Wikimedia Commons; Clusters of long green bean pods hanging from a climbing bean vine: Nirajan_pant, CC BY-SA 3.0, via Wikimedia Commons; Cucumber plants growing in a greenhouse bed: HARTLEPOOLMARINA2014, CC BY-SA 4.0, via Wikimedia Commons; Zucchini fruit on the plant: Schlaghecken Josef, CC BY-SA 4.0, via Wikimedia Commons; Lettuce plants growing in rows: AfroBrazilian, CC BY-SA 3.0, via Wikimedia Commons; Long rows of green onion plants growing in sandy farm soil: ליזי שאנן, CC BY 2.5, via Wikimedia Commons; Neat rows of young garlic shoots growing in dark tilled soil: Timothy A. Gonsalves, CC BY-SA 4.0, via Wikimedia Commons; Rows of young pea plants in a vegetable patch: Kolforn (Kolforn), CC BY-SA 4.0, via Wikimedia Commons; Young watermelon plant in a garden: Forest and Kim Starr, CC BY 3.0 us, via Wikimedia Commons.