Frost Report

All states Iowa

Frost dates for Clarence, IA

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

April 27

typical year

Safe to plant

May 13

frost is over in 9 of 10 years

First fall frost

October 10

typical year

Growing season

165 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 – Mar 30 – Apr 13 –
Spinach – Mar 16 – Apr 6 Aug 15 – 29
Lettuce – Mar 30 – Apr 20 Aug 15 – 29
Radishes – Mar 30 – May 11 Aug 29 – Sep 12
Onions – Mar 30 – Apr 13 –
Potatoes – Apr 6 – 20 –
Carrots – Apr 6 – 27 Jul 18 – Aug 1
Beets – Mar 30 – Apr 13 Aug 1 – 15
Kale Feb 16 – Mar 2 Mar 30 – Apr 13 Aug 1 – 15
Broccoli Feb 16 – Mar 2 Apr 13 – 27 Aug 1 – 15
Cabbage Feb 2 – 16 Mar 30 – Apr 13 Aug 1 – 15
Garlic – – Aug 29 – Sep 19
Warm-season crops
Tomatoes Mar 18 – Apr 1 May 13 – 27 –
Peppers Mar 11 – 25 May 20 – Jun 3 –
Cucumbers – May 13 – Jun 3 –
Zucchini – May 13 – Jun 10 –
Pumpkins – May 13 – Jun 3 –
Green beans – May 13 – Aug 1 –
Sweet corn – May 13 – Jun 10 –
Basil Apr 8 – 22 May 20 – 27 –

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 May 13April 27April 11
Fall frost before September 25October 10October 23

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 April 16 (May 4 in a late year), and the first one in fall around October 20.

Towns that use these dates

This is the nearest NOAA station with frost records for 11 towns.

Clarence, Lowden, Wheatland, Grand Mound, Wyoming, Oxford Junction, Lost Nation, Calamus, Dixon, New Liberty, Toronto

Where these dates come from

NOAA weather station LOWDEN, IA US (USC00134963), 1991–2020 climate normals. It's the nearest station for 10 zip codes, all within 14 miles:

52216, 52254, 52255, 52323, 52362, 52721, 52729, 52751, 52765, 52777

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