Frost Report

All states Colorado

Frost dates for Sheep Mtn, 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 27

typical year

Safe to plant

June 10

frost is over in 9 of 10 years

First fall frost

September 25

typical year

Growing season

119 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 29 – May 13 –
Spinach – Apr 15 – May 6 Jul 31 – Aug 14
Lettuce – Apr 29 – May 20 Jul 31 – Aug 14
Radishes – Apr 29 – Jun 10 Aug 14 – 28
Onions – Apr 29 – May 13 –
Potatoes – May 6 – 20 –
Carrots – May 6 – 27 Jul 3 – 17
Beets – Apr 29 – May 13 Jul 17 – 31
Kale Mar 18 – Apr 1 Apr 29 – May 13 Jul 17 – 31
Broccoli Mar 18 – Apr 1 May 13 – 27 Jul 17 – 31
Cabbage Mar 4 – 18 Apr 29 – May 13 Jul 17 – 31
Garlic – – Aug 14 – Sep 4
Warm-season crops
Tomatoes Apr 15 – 29 Jun 10 – 24 –
Peppers Apr 8 – 22 Jun 17 – Jul 1 –
Cucumbers – Jun 10 – Jul 1 –
Zucchini – Jun 10 – Jul 8 –
Pumpkins – Jun 10 – Jul 1 –
Green beans – Jun 10 – Jul 17 –
Sweet corn – Jun 10 – Jul 8 –
Basil May 6 – 20 Jun 17 – 24 –

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 June 10May 27May 12
Fall frost before September 11September 25October 8

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 May 13 (May 30 in a late year), and the first one in fall around October 4.

Where these dates come from

NOAA weather station SHEEP MTN, CO US (USC00057572), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 5 miles:

81040

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