When Is the Last Frost?

Porterville, CA frost dates

Last spring frostJan 20median date
First fall frostDec 13median date
Growing season327 daysfrost-free
Hardiness zone9bZone 9b

Frost is light and occasional here — typically a few cold nights around midwinter (about 15 a year). Cover tender plants when frost is forecast.

How Porterville compares

Frost probability

Last spring frost
Chance of frost afterDate
90% (early)December 25
50% (median)January 20
10% (safe for tender plants)February 22
First fall frost
Chance of frost beforeDate
10% (early)November 26
50% (median)December 13
90% (late)January 6

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

Porterville, 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:

About these dates

Based on 1991–2020 NOAA climate normals for the Porterville, CA weather station, 2 km away (elevation 394 ft (120 m)).

ZIP codes in Porterville: 93257 93258

Frost dates near Porterville

Frequently asked questions

When is the last frost in Porterville, CA?

The median last spring frost in Porterville, CA is January 20. There is still about a 10% chance of frost after February 22, so wait until then to plant frost-tender crops like tomatoes and peppers.

When is the first frost in Porterville, CA?

The median first fall frost is December 13, with about a 10% chance of frost before November 26.

How long is the growing season in Porterville, CA?

About 327 days between the median last spring frost and first fall frost.

What planting zone is Porterville, CA?

Porterville, CA is in USDA hardiness zone 9b.

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