Frost Report

All states California

Frost dates for Petaluma, CA

When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.

Last spring frost

February 28

typical year

Safe to plant

April 6

frost is over in 9 of 10 years

First fall frost

November 25

typical year

Growing season

271 days

frost-free, typical year

When to plant

Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.

CropStart indoorsPlant outsideFall planting
Cool-season crops
Peas – Jan 31 – Feb 14 –
Spinach – Jan 17 – Feb 7 Sep 30 – Oct 14
Lettuce – Jan 31 – Feb 21 Sep 30 – Oct 14
Radishes – Jan 31 – Mar 14 Oct 14 – 28
Onions – Jan 31 – Feb 14 –
Potatoes – Feb 7 – 21 –
Carrots – Feb 7 – 28 Sep 2 – 16
Beets – Jan 31 – Feb 14 Sep 16 – 30
Kale Dec 20 – Jan 3 Jan 31 – Feb 14 Sep 16 – 30
Broccoli Dec 20 – Jan 3 Feb 14 – 28 Sep 16 – 30
Cabbage Dec 6 – 20 Jan 31 – Feb 14 Sep 16 – 30
Garlic – – Oct 14 – Nov 4
Warm-season crops
Tomatoes Feb 9 – 23 Apr 6 – 20 –
Peppers Feb 2 – 16 Apr 13 – 27 –
Cucumbers – Apr 6 – 27 –
Zucchini – Apr 6 – May 4 –
Pumpkins – Apr 6 – 27 –
Green beans – Apr 6 – Sep 16 –
Sweet corn – Apr 6 – May 4 –
Basil Mar 2 – 16 Apr 13 – 20 –

Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.

The year at a glance

Start indoors Plant outside Fall planting

The chance of frost, by date

1 year in 10Half of years9 years in 10
Spring frost after April 6February 28January 24
Fall frost before November 9November 25December 16

Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.

Hard freeze (28°F)

A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around January 17 (February 24 in a late year), and the first one in fall around December 9.

Towns that use these dates

This is the nearest NOAA station with frost records for 2 towns.

Petaluma, Cotati

Where these dates come from

NOAA weather station PETALUMA AP, CA US (USC00046826), 1991–2020 climate normals. It's the nearest station for 5 zip codes, all within 8 miles:

94928, 94931, 94951, 94952, 94954

Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.