Harman US

Frost Dates for Westview Circle, WY

Last spring frost
May 19
First fall frost
Sep 22
Growing season
125 days
Hardiness zone
5a

In an average year around Westview Circle, WY, the last spring frost (32°F) is about May 19 and the first fall frost is about Sep 22, giving roughly a 125-day growing season. To be safe most years, wait until May 7 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 - Westview Circle, WY
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Jun 20 Jun 1 May 18
Freeze (32°F) Jun 2 May 19 May 7
Hard (28°F) May 22 May 9 Apr 27
Severe (24°F) May 12 Apr 30 Apr 15
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Jun 20 Jun 12 Jun 7 Jun 4 Jun 1 May 29 May 26 May 23 May 18
32°F Jun 2 May 28 May 24 May 22 May 19 May 16 May 14 May 10 May 7
28°F May 22 May 17 May 13 May 11 May 9 May 6 May 4 May 1 Apr 27
24°F May 12 May 7 May 4 May 2 Apr 30 Apr 27 Apr 24 Apr 20 Apr 15
20°F May 3 Apr 28 Apr 24 Apr 20 Apr 16 Apr 13 Apr 10 Apr 6 Apr 1
16°F Apr 24 Apr 17 Apr 12 Apr 8 Apr 4 Apr 1 Mar 29 Mar 24 Mar 15

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 - Westview Circle, WY
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Aug 28 Sep 12 Sep 26
Freeze (32°F) Sep 8 Sep 22 Oct 4
Hard (28°F) Sep 17 Oct 1 Oct 14
Severe (24°F) Sep 27 Oct 10 Oct 24
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Aug 28 Sep 2 Sep 6 Sep 10 Sep 12 Sep 15 Sep 18 Sep 21 Sep 26
32°F Sep 8 Sep 13 Sep 16 Sep 19 Sep 22 Sep 25 Sep 28 Oct 1 Oct 4
28°F Sep 17 Sep 22 Sep 26 Sep 29 Oct 1 Oct 3 Oct 6 Oct 10 Oct 14
24°F Sep 27 Oct 1 Oct 5 Oct 8 Oct 10 Oct 13 Oct 16 Oct 19 Oct 24
20°F Oct 5 Oct 11 Oct 14 Oct 17 Oct 20 Oct 23 Oct 25 Oct 28 Nov 2
16°F Oct 14 Oct 18 Oct 22 Oct 25 Oct 28 Oct 31 Nov 3 Nov 7 Nov 13

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: Wheatland 4 N, Wy, about 11.9 miles away@if(!empty($station['elevation_ft'])), at 4,638 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 Westview Circle, WY?

On average, the last spring frost (32°F) around Westview Circle, WY is about May 19. In cooler years it can run later, so for a safer bet many gardeners wait until May 7.

When is the first frost in the fall?

The first fall frost around Westview Circle, WY typically arrives about Sep 22. 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 19 on average, or May 7 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 82201 Planting calendar → Wyoming frost dates →

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