Frost Report

All states Iowa

Frost dates for Spirit Lake, 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 28

typical year

Safe to plant

May 9

frost is over in 9 of 10 years

First fall frost

October 11

typical year

Growing season

164 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 31 – Apr 14 –
Spinach – Mar 17 – Apr 7 Aug 16 – 30
Lettuce – Mar 31 – Apr 21 Aug 16 – 30
Radishes – Mar 31 – May 12 Aug 30 – Sep 13
Onions – Mar 31 – Apr 14 –
Potatoes – Apr 7 – 21 –
Carrots – Apr 7 – 28 Jul 19 – Aug 2
Beets – Mar 31 – Apr 14 Aug 2 – 16
Kale Feb 17 – Mar 3 Mar 31 – Apr 14 Aug 2 – 16
Broccoli Feb 17 – Mar 3 Apr 14 – 28 Aug 2 – 16
Cabbage Feb 3 – 17 Mar 31 – Apr 14 Aug 2 – 16
Garlic – – Aug 30 – Sep 20
Warm-season crops
Tomatoes Mar 14 – 28 May 9 – 23 –
Peppers Mar 7 – 21 May 16 – 30 –
Cucumbers – May 9 – 30 –
Zucchini – May 9 – Jun 6 –
Pumpkins – May 9 – 30 –
Green beans – May 9 – Aug 2 –
Sweet corn – May 9 – Jun 6 –
Basil Apr 4 – 18 May 16 – 23 –

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 9April 28April 14
Fall frost before September 27October 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 19 (May 2 in a late year), and the first one in fall around October 21.

Towns that use these dates

This is the nearest NOAA station with frost records for 5 towns.

Spirit Lake, Okoboji, Orleans, Terril, Superior

Where these dates come from

NOAA weather station SPIRIT LAKE, IA US (USC00137859), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 12 miles:

51360, 51363, 51364

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