Harman US

Frost Dates for Two Buttes, CO

Last spring frost
Apr 30
First fall frost
Oct 14
Growing season
166 days
Hardiness zone
6b

In an average year around Two Buttes, CO, the last spring frost (32°F) is about Apr 30 and the first fall frost is about Oct 14, giving roughly a 166-day growing season. To be safe most years, wait until Apr 17 before setting out tender plants.

Last spring frost

Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.

Last spring frost - Two Buttes, CO
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) May 23 May 9 Apr 29
Freeze (32°F) May 12 Apr 30 Apr 17
Hard (28°F) May 4 Apr 19 Apr 5
Severe (24°F) Apr 23 Apr 8 Mar 23
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F May 23 May 19 May 15 May 12 May 9 May 7 May 4 May 2 Apr 29
32°F May 12 May 7 May 4 May 2 Apr 30 Apr 28 Apr 24 Apr 20 Apr 17
28°F May 4 Apr 29 Apr 25 Apr 22 Apr 19 Apr 17 Apr 13 Apr 10 Apr 5
24°F Apr 23 Apr 19 Apr 15 Apr 12 Apr 8 Apr 6 Apr 3 Mar 30 Mar 23
20°F Apr 15 Apr 9 Apr 5 Apr 2 Mar 30 Mar 26 Mar 21 Mar 16 Mar 9
16°F Apr 5 Mar 29 Mar 24 Mar 19 Mar 15 Mar 11 Mar 8 Mar 3 Feb 26

First fall frost

Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.

First fall frost - Two Buttes, CO
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Sep 24 Oct 5 Oct 15
Freeze (32°F) Oct 1 Oct 14 Oct 24
Hard (28°F) Oct 9 Oct 22 Nov 2
Severe (24°F) Oct 18 Nov 1 Nov 13
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Sep 24 Sep 27 Sep 30 Oct 3 Oct 5 Oct 7 Oct 9 Oct 12 Oct 15
32°F Oct 1 Oct 5 Oct 8 Oct 11 Oct 14 Oct 16 Oct 18 Oct 21 Oct 24
28°F Oct 9 Oct 14 Oct 17 Oct 19 Oct 22 Oct 25 Oct 27 Oct 29 Nov 2
24°F Oct 18 Oct 22 Oct 26 Oct 30 Nov 1 Nov 3 Nov 6 Nov 9 Nov 13
20°F Oct 26 Nov 1 Nov 3 Nov 6 Nov 9 Nov 12 Nov 15 Nov 18 Nov 23
16°F Nov 2 Nov 6 Nov 11 Nov 14 Nov 17 Nov 20 Nov 24 Nov 28 Dec 3

Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.

Where this data comes from

These dates are computed from the nearest official weather station with long-term records: Walsh 1 W, Co, about 14.4 miles away@if(!empty($station['elevation_ft'])), at 3,978 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.

@endif
How we calculate these dates

Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.

Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.

Frequently asked questions

When is the last frost in Two Buttes, CO?

On average, the last spring frost (32°F) around Two Buttes, CO is about Apr 30. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 17.

When is the first frost in the fall?

The first fall frost around Two Buttes, CO typically arrives about Oct 14. Count back by a crop's days to maturity to find the latest date you can plant it.

When can I plant tomatoes and other tender crops?

Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 30 on average, or Apr 17 to be safe most years.

How long is the growing season here?

The frost-free growing season (between the last spring and first fall 32°F frost) is about 166 days in a typical year.

Are these dates a forecast for this year?

No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.

Local weather for 81084 Planting calendar → Colorado frost dates →

Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026