Last frost date in Fort Collins, Colorado
May 2
Average last frost in spring. In an early year (1 in 10) it's over by April 18; in a late year (1 in 10) it comes after May 14.
October 7
Average first frost in fall. 1 year in 10 it comes by September 24.
Source: NOAA U.S. Climate Normals 1991–2020, station Ft Collins (USC00053005), 2.2 miles from Fort Collins, elevation 5,004 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Apr 18 | May 2 | May 14 |
| First frost in fall | Sept 24 | Oct 7 | Oct 20 |
Frost-free days in an average year: 157
| Chance in a year | Average last in spring | Average first in fall | |
|---|---|---|---|
| Light frost (36°F) | Every year | May 12 | Sept 29 |
| Frost (32°F) | Every year | May 2 | Oct 7 |
| Hard freeze (28°F) | Every year | Apr 20 | Oct 17 |
Nights at 32°F or colder in an average year: 150
What to plant now in Fort Collins
- Spring planting calendar for an average last frost around April 30 Fort Collins: May 2
- Fall planting calendar for an average first frost around October 10 Fort Collins: October 7
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. How we match the table.