Frost Report

All states Illinois

Frost dates for Mattoon, IL

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 11

typical year

Safe to plant

April 28

frost is over in 9 of 10 years

First fall frost

October 29

typical year

Growing season

199 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 14 – 28 –
Spinach – Feb 28 – Mar 21 Sep 3 – 17
Lettuce – Mar 14 – Apr 4 Sep 3 – 17
Radishes – Mar 14 – Apr 25 Sep 17 – Oct 1
Onions – Mar 14 – 28 –
Potatoes – Mar 21 – Apr 4 –
Carrots – Mar 21 – Apr 11 Aug 6 – 20
Beets – Mar 14 – 28 Aug 20 – Sep 3
Kale Jan 31 – Feb 14 Mar 14 – 28 Aug 20 – Sep 3
Broccoli Jan 31 – Feb 14 Mar 28 – Apr 11 Aug 20 – Sep 3
Cabbage Jan 17 – 31 Mar 14 – 28 Aug 20 – Sep 3
Garlic – – Sep 17 – Oct 8
Warm-season crops
Tomatoes Mar 3 – 17 Apr 28 – May 12 –
Peppers Feb 24 – Mar 10 May 5 – 19 –
Cucumbers – Apr 28 – May 19 –
Zucchini – Apr 28 – May 26 –
Pumpkins – Apr 28 – May 19 –
Green beans – Apr 28 – Aug 20 –
Sweet corn – Apr 28 – May 26 –
Basil Mar 24 – Apr 7 May 5 – 12 –

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 28April 11March 31
Fall frost before October 15October 29November 9

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 2 (April 17 in a late year), and the first one in fall around November 7.

Towns that use these dates

This is the nearest NOAA station with frost records for 1 town.

Mattoon

Where these dates come from

NOAA weather station MATTOON, IL US (USC00115430), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 8 miles:

61931, 61938, 62469

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