Frost Report

All states Iowa

Frost dates for Parkersburg, 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 8

frost is over in 9 of 10 years

First fall frost

October 8

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 13 – 27
Lettuce – Mar 30 – Apr 20 Aug 13 – 27
Radishes – Mar 30 – May 11 Aug 27 – Sep 10
Onions – Mar 30 – Apr 13 –
Potatoes – Apr 6 – 20 –
Carrots – Apr 6 – 27 Jul 16 – 30
Beets – Mar 30 – Apr 13 Jul 30 – Aug 13
Kale Feb 16 – Mar 2 Mar 30 – Apr 13 Jul 30 – Aug 13
Broccoli Feb 16 – Mar 2 Apr 13 – 27 Jul 30 – Aug 13
Cabbage Feb 2 – 16 Mar 30 – Apr 13 Jul 30 – Aug 13
Garlic – – Aug 27 – Sep 17
Warm-season crops
Tomatoes Mar 13 – 27 May 8 – 22 –
Peppers Mar 6 – 20 May 15 – 29 –
Cucumbers – May 8 – 29 –
Zucchini – May 8 – Jun 5 –
Pumpkins – May 8 – 29 –
Green beans – May 8 – Jul 30 –
Sweet corn – May 8 – Jun 5 –
Basil Apr 3 – 17 May 15 – 22 –

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 8April 27April 12
Fall frost before September 24October 8October 22

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 (April 30 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 8 towns.

Parkersburg, Shell Rock, Clarksville, Aplington, Greene, Allison, Dumont, Bristow

Where these dates come from

NOAA weather station ALLISON, IA US (USC00130157), 1991–2020 climate normals. It's the nearest station for 10 zip codes, all within 14 miles:

50602, 50604, 50608, 50611, 50619, 50625, 50636, 50649, 50665, 50670

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