Frost Report

All states Colorado

Frost dates for Lamar, 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 2

typical year

Safe to plant

May 17

frost is over in 9 of 10 years

First fall frost

October 7

typical year

Growing season

157 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 4 – 18 –
Spinach – Mar 21 – Apr 11 Aug 12 – 26
Lettuce – Apr 4 – 25 Aug 12 – 26
Radishes – Apr 4 – May 16 Aug 26 – Sep 9
Onions – Apr 4 – 18 –
Potatoes – Apr 11 – 25 –
Carrots – Apr 11 – May 2 Jul 15 – 29
Beets – Apr 4 – 18 Jul 29 – Aug 12
Kale Feb 21 – Mar 7 Apr 4 – 18 Jul 29 – Aug 12
Broccoli Feb 21 – Mar 7 Apr 18 – May 2 Jul 29 – Aug 12
Cabbage Feb 7 – 21 Apr 4 – 18 Jul 29 – Aug 12
Garlic – – Aug 26 – Sep 16
Warm-season crops
Tomatoes Mar 22 – Apr 5 May 17 – 31 –
Peppers Mar 15 – 29 May 24 – Jun 7 –
Cucumbers – May 17 – Jun 7 –
Zucchini – May 17 – Jun 14 –
Pumpkins – May 17 – Jun 7 –
Green beans – May 17 – Jul 29 –
Sweet corn – May 17 – Jun 14 –
Basil Apr 12 – 26 May 24 – 31 –

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 17May 2April 19
Fall frost before September 28October 7October 19

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 22 (May 6 in a late year), and the first one in fall around October 16.

Towns that use these dates

This is the nearest NOAA station with frost records for 2 towns.

Lamar, Wiley

Where these dates come from

NOAA weather station LAMAR MUNI AP, CO US (USW00003013), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 7 miles:

81052

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