Harman US

Frost Dates for Towaoc, CO

Last spring frost
May 27
First fall frost
Sep 28
Growing season
125 days
Hardiness zone
7a

In an average year around Towaoc, CO, the last spring frost (32°F) is about May 27 and the first fall frost is about Sep 28, giving roughly a 125-day growing season. To be safe most years, wait until May 9 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 - Towaoc, CO
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Jun 24 Jun 9 May 26
Freeze (32°F) Jun 11 May 27 May 9
Hard (28°F) May 31 May 8 Apr 25
Severe (24°F) May 10 Apr 25 Apr 9
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Jun 24 Jun 20 Jun 16 Jun 12 Jun 9 Jun 6 Jun 3 May 31 May 26
32°F Jun 11 Jun 6 Jun 2 May 31 May 27 May 23 May 20 May 15 May 9
28°F May 31 May 20 May 15 May 11 May 8 May 5 May 2 Apr 30 Apr 25
24°F May 10 May 4 May 1 Apr 28 Apr 25 Apr 21 Apr 18 Apr 14 Apr 9
20°F Apr 29 Apr 22 Apr 18 Apr 14 Apr 10 Apr 7 Apr 3 Mar 30 Mar 21
16°F Apr 10 Apr 5 Mar 31 Mar 26 Mar 20 Mar 15 Mar 11 Mar 7 Mar 2

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 - Towaoc, CO
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Sep 8 Sep 20 Sep 30
Freeze (32°F) Sep 17 Sep 28 Oct 10
Hard (28°F) Sep 26 Oct 7 Oct 21
Severe (24°F) Oct 4 Oct 17 Nov 1
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Sep 8 Sep 12 Sep 14 Sep 17 Sep 20 Sep 22 Sep 24 Sep 26 Sep 30
32°F Sep 17 Sep 21 Sep 23 Sep 26 Sep 28 Oct 1 Oct 3 Oct 5 Oct 10
28°F Sep 26 Sep 30 Oct 3 Oct 5 Oct 7 Oct 10 Oct 13 Oct 16 Oct 21
24°F Oct 4 Oct 8 Oct 11 Oct 14 Oct 17 Oct 20 Oct 23 Oct 27 Nov 1
20°F Oct 13 Oct 18 Oct 21 Oct 24 Oct 28 Oct 31 Nov 3 Nov 6 Nov 12
16°F Oct 22 Oct 28 Nov 1 Nov 5 Nov 8 Nov 11 Nov 15 Nov 19 Nov 23

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: Cortez Montezuma Co Ap, Co, about 5.9 miles away@if(!empty($station['elevation_ft'])), at 5,914 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.

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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 Towaoc, CO?

On average, the last spring frost (32°F) around Towaoc, CO is about May 27. In cooler years it can run later, so for a safer bet many gardeners wait until May 9.

When is the first frost in the fall?

The first fall frost around Towaoc, CO typically arrives about Sep 28. 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 May 27 on average, or May 9 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 125 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 81321 Planting calendar → Colorado frost dates →

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