Last spring frost
May 31
Frost Dates for Red Feather Lakes, CO
First fall frost
Sep 19
Growing season
110 days
Hardiness zone
5b
In an average year around Red Feather Lakes, CO, the last spring frost (32°F) is about May 31 and the first fall frost is about Sep 19, giving roughly a 110-day growing season. To be safe most years, wait until May 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.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Jun 30 | Jun 14 | May 31 |
| Freeze (32°F) | Jun 15 | May 31 | May 17 |
| Hard (28°F) | May 31 | May 16 | May 3 |
| Severe (24°F) | May 17 | May 2 | Apr 20 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 30 | Jun 24 | Jun 20 | Jun 17 | Jun 14 | Jun 11 | Jun 8 | Jun 4 | May 31 |
| 32°F | Jun 15 | Jun 9 | Jun 4 | Jun 2 | May 31 | May 27 | May 24 | May 21 | May 17 |
| 28°F | May 31 | May 26 | May 22 | May 19 | May 16 | May 13 | May 10 | May 6 | May 3 |
| 24°F | May 17 | May 11 | May 8 | May 4 | May 2 | Apr 30 | Apr 28 | Apr 25 | Apr 20 |
| 20°F | May 6 | May 1 | Apr 29 | Apr 25 | Apr 22 | Apr 20 | Apr 16 | Apr 12 | Apr 9 |
| 16°F | Apr 30 | Apr 23 | Apr 19 | Apr 14 | Apr 10 | Apr 7 | Apr 3 | Mar 30 | Mar 23 |
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.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Aug 23 | Sep 8 | Sep 22 |
| Freeze (32°F) | Sep 5 | Sep 19 | Oct 1 |
| Hard (28°F) | Sep 14 | Sep 29 | Oct 12 |
| Severe (24°F) | Sep 23 | Oct 8 | Oct 25 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 23 | Aug 31 | Sep 3 | Sep 5 | Sep 8 | Sep 11 | Sep 14 | Sep 17 | Sep 22 |
| 32°F | Sep 5 | Sep 10 | Sep 13 | Sep 16 | Sep 19 | Sep 22 | Sep 25 | Sep 28 | Oct 1 |
| 28°F | Sep 14 | Sep 19 | Sep 22 | Sep 26 | Sep 29 | Oct 1 | Oct 3 | Oct 7 | Oct 12 |
| 24°F | Sep 23 | Sep 29 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 19 | Oct 25 |
| 20°F | Oct 4 | Oct 9 | Oct 13 | Oct 16 | Oct 20 | Oct 22 | Oct 26 | Oct 30 | Nov 4 |
| 16°F | Oct 13 | Oct 18 | Oct 22 | Oct 26 | Oct 30 | Nov 1 | Nov 5 | Nov 9 | Nov 14 |
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
@endif These dates are computed from the nearest official weather station with long-term records: Virginia Dale 7 Ene, Co, about 10.4 miles away@if(!empty($station['elevation_ft'])), at 7,015 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
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 Red Feather Lakes, CO?
On average, the last spring frost (32°F) around Red Feather Lakes, CO is about May 31. In cooler years it can run later, so for a safer bet many gardeners wait until May 17.
When is the first frost in the fall?
The first fall frost around Red Feather Lakes, CO typically arrives about Sep 19. 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 31 on average, or May 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 110 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 80536 Planting calendar → Colorado frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026