Frost Report

All states Iowa

Frost dates for Waukon, 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

May 2

typical year

Safe to plant

May 16

frost is over in 9 of 10 years

First fall frost

October 11

typical year

Growing season

161 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 – Apr 4 – 18 –
Spinach – Mar 21 – Apr 11 Aug 16 – 30
Lettuce – Apr 4 – 25 Aug 16 – 30
Radishes – Apr 4 – May 16 Aug 30 – Sep 13
Onions – Apr 4 – 18 –
Potatoes – Apr 11 – 25 –
Carrots – Apr 11 – May 2 Jul 19 – Aug 2
Beets – Apr 4 – 18 Aug 2 – 16
Kale Feb 21 – Mar 7 Apr 4 – 18 Aug 2 – 16
Broccoli Feb 21 – Mar 7 Apr 18 – May 2 Aug 2 – 16
Cabbage Feb 7 – 21 Apr 4 – 18 Aug 2 – 16
Garlic – – Aug 30 – Sep 20
Warm-season crops
Tomatoes Mar 21 – Apr 4 May 16 – 30 –
Peppers Mar 14 – 28 May 23 – Jun 6 –
Cucumbers – May 16 – Jun 6 –
Zucchini – May 16 – Jun 13 –
Pumpkins – May 16 – Jun 6 –
Green beans – May 16 – Aug 2 –
Sweet corn – May 16 – Jun 13 –
Basil Apr 11 – 25 May 23 – 30 –

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 16May 2April 17
Fall frost before September 28October 11October 24

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 21 (May 6 in a late year), and the first one in fall around October 22.

Towns that use these dates

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

Waukon, Waterville

Where these dates come from

NOAA weather station WAUKON, IA US (USC00138755), 1991–2020 climate normals. It's the nearest station for 4 zip codes, all within 12 miles:

52140, 52151, 52170, 52172

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