Frost Report

All states Colorado

Frost dates for Burlington, CO

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 6

typical year

Safe to plant

May 19

frost is over in 9 of 10 years

First fall frost

October 9

typical year

Growing season

155 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 8 – 22 –
Spinach – Mar 25 – Apr 15 Aug 14 – 28
Lettuce – Apr 8 – 29 Aug 14 – 28
Radishes – Apr 8 – May 20 Aug 28 – Sep 11
Onions – Apr 8 – 22 –
Potatoes – Apr 15 – 29 –
Carrots – Apr 15 – May 6 Jul 17 – 31
Beets – Apr 8 – 22 Jul 31 – Aug 14
Kale Feb 25 – Mar 11 Apr 8 – 22 Jul 31 – Aug 14
Broccoli Feb 25 – Mar 11 Apr 22 – May 6 Jul 31 – Aug 14
Cabbage Feb 11 – 25 Apr 8 – 22 Jul 31 – Aug 14
Garlic – – Aug 28 – Sep 18
Warm-season crops
Tomatoes Mar 24 – Apr 7 May 19 – Jun 2 –
Peppers Mar 17 – 31 May 26 – Jun 9 –
Cucumbers – May 19 – Jun 9 –
Zucchini – May 19 – Jun 16 –
Pumpkins – May 19 – Jun 9 –
Green beans – May 19 – Jul 31 –
Sweet corn – May 19 – Jun 16 –
Basil Apr 14 – 28 May 26 – Jun 2 –

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 19May 6April 23
Fall frost before September 27October 9October 20

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 27 (May 9 in a late year), and the first one in fall around October 18.

Towns that use these dates

This is the nearest NOAA station with frost records for 3 towns.

Burlington, Bethune, Kanorado, KS

Where these dates come from

NOAA weather station BURLINGTON, CO US (USC00051121), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 15 miles:

67741, 80807

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