Frost history / Ft Collins 4 E, CO
Ft Collins 4 E, CO: frost dates by year
Last spring and first fall frost at NOAA station USC00053006, 1991 to 2020, measured from daily minimum temperatures.
Elevation 4,920 ft, 40.576, -105.024. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 3 | Oct 5 |
| Earliest | Apr 15 (2007) | Sep 8 (2020) |
| Latest | May 24 (2002) | Oct 24 (2015) |
| Trend | 0.7 days earlier per decade | 3.5 days later per decade |
| Years with data | 29 | 30 |
At 28°F (hard freeze) the median last spring date is Apr 27 and the median first fall date is Oct 13.
The trend is a straight-line fit through the years with a freeze. A positive spring trend means the last frost now comes later. Short or patchy records give noisy trends.
Chart
Last spring frost (32°F)
First fall frost (32°F)
Dots are single years. The gray line is the median, the green line the fitted trend.
Year by year
| Year | Last spring 32°F | First fall 32°F | Last spring 28°F | First fall 28°F |
|---|---|---|---|---|
| 2020 | Apr 19 | Sep 8 | Apr 18 | Oct 15 |
| 2019 | May 11 | Oct 7 | Apr 12 | Oct 10 |
| 2018 | Apr 27 | Oct 10 | Apr 25 | Oct 13 |
| 2017 | no data | Oct 3 | no data | Oct 10 |
| 2016 | May 2 | Oct 5 | May 2 | Oct 20 |
| 2015 | May 11 | Oct 24 | May 11 | Nov 6 |
| 2014 | May 14 | Sep 13 | Apr 17 | Oct 29 |
| 2013 | May 3 | Oct 6 | May 3 | Oct 16 |
| 2012 | Apr 17 | Oct 5 | Apr 8 | Oct 7 |
| 2011 | May 5 | Oct 18 | May 3 | Oct 19 |
| 2010 | May 13 | Oct 19 | May 8 | Oct 27 |
| 2009 | Apr 27 | Oct 2 | Apr 7 | Oct 3 |
| 2008 | May 14 | Oct 13 | May 11 | Oct 14 |
| 2007 | Apr 15 | Oct 8 | Apr 14 | Oct 21 |
| 2006 | May 11 | Oct 13 | Apr 26 | Oct 17 |
| 2005 | May 12 | Oct 7 | Apr 30 | Oct 7 |
| 2004 | May 2 | Oct 23 | May 1 | Oct 30 |
| 2003 | May 11 | Oct 1 | Apr 9 | Oct 14 |
| 2002 | May 24 | Oct 12 | May 9 | Oct 13 |
| 2001 | May 3 | Sep 9 | Apr 1 | Oct 5 |
| 2000 | May 13 | Sep 22 | May 13 | Sep 24 |
| 1999 | May 12 | Sep 28 | Apr 17 | Sep 28 |
| 1998 | Apr 29 | Oct 6 | Apr 19 | Oct 18 |
| 1997 | May 12 | Oct 9 | Apr 14 | Oct 13 |
| 1996 | Apr 29 | Sep 26 | Apr 29 | Sep 27 |
| 1995 | May 4 | Sep 20 | Apr 27 | Sep 22 |
| 1994 | Apr 30 | Sep 21 | Apr 28 | Sep 22 |
| 1993 | May 2 | Sep 13 | May 2 | Sep 14 |
| 1992 | Apr 26 | Oct 7 | Apr 25 | Oct 7 |
| 1991 | May 3 | Sep 24 | May 3 | Oct 19 |
"none" means the station recorded no freeze at that threshold in that half of the year. "no data" means more than 10% of the season's daily readings were missing. Years with no usable data are left out. See the methodology for the rules, and the ZIP lookup for 1991 to 2020 frost probabilities.