Frost Report

All states Colorado

Frost dates for Lemon Dam, 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 28

typical year

Safe to plant

June 10

frost is over in 9 of 10 years

First fall frost

September 30

typical year

Growing season

122 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 30 – May 14 –
Spinach – Apr 16 – May 7 Aug 5 – 19
Lettuce – Apr 30 – May 21 Aug 5 – 19
Radishes – Apr 30 – Jun 11 Aug 19 – Sep 2
Onions – Apr 30 – May 14 –
Potatoes – May 7 – 21 –
Carrots – May 7 – 28 Jul 8 – 22
Beets – Apr 30 – May 14 Jul 22 – Aug 5
Kale Mar 19 – Apr 2 Apr 30 – May 14 Jul 22 – Aug 5
Broccoli Mar 19 – Apr 2 May 14 – 28 Jul 22 – Aug 5
Cabbage Mar 5 – 19 Apr 30 – May 14 Jul 22 – Aug 5
Garlic – – Aug 19 – Sep 9
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 22 –
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 28May 13
Fall frost before September 15September 30October 12

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 12 (May 30 in a late year), and the first one in fall around October 10.

Where these dates come from

NOAA weather station LEMON DAM, CO US (USC00054934), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 14 miles:

81301

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