Last Frost Day

Frost history / Rye 1SW, CO

Rye 1SW, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00057317, 1997 to 2025, measured from daily minimum temperatures.

Elevation 7,141 ft, 37.914, -104.948. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 12Oct 7
EarliestApr 16 (2012)Sep 8 (2020)
LatestJun 6 (1998)Oct 30 (2024)
Trend4.9 days earlier per decade7.7 days later per decade
Years with data2828

At 28°F (hard freeze) the median last spring date is Apr 30 and the median first fall date is Oct 17.

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)

Mar 31Apr 15Apr 30May 15May 30Jun 142000201020201998: Jun 61999: May 122000: May 132001: May 212002: May 242003: May 112004: May 142005: May 122006: May 112007: May 242008: May 152009: Apr 282010: May 132011: May 32012: Apr 162013: May 52014: May 142015: May 112016: May 22017: May 202018: Apr 252019: May 232020: May 102021: May 122022: May 222023: Apr 282024: May 42025: May 6

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 112000201020201997: Oct 91998: Oct 51999: Sep 282000: Sep 242001: Sep 92002: Oct 22003: Sep 132004: Sep 232005: Oct 62006: Sep 222007: Oct 82008: Oct 132010: Oct 262011: Oct 192012: Oct 42013: Oct 52014: Oct 32015: Oct 282016: Oct 72017: Oct 92018: Oct 102019: Oct 102020: Sep 82021: Oct 132022: Oct 242023: Oct 132024: Oct 302025: Oct 19

Dots are single years. The gray line is the median, the green line the fitted trend.

Year by year

YearLast spring 32°FFirst fall 32°FLast spring 28°FFirst fall 28°F
2025May 6Oct 19Apr 20Oct 28
2024May 4Oct 30Apr 20Oct 31
2023Apr 28Oct 13Apr 23Oct 14
2022May 22Oct 24May 21Oct 25
2021May 12Oct 13Apr 22Oct 15
2020May 10Sep 8Apr 17Sep 9
2019May 23Oct 10Apr 14Oct 10
2018Apr 25Oct 10Apr 25Oct 14
2017May 20Oct 9Apr 30Oct 10
2016May 2Oct 7May 2Nov 18
2015May 11Oct 28Apr 18Nov 6
2014May 14Oct 3May 13Nov 10
2013May 5Oct 5May 3Oct 18
2012Apr 16Oct 4Mar 20Oct 7
2011May 3Oct 19May 2Oct 26
2010May 13Oct 26May 8Oct 26
2009Apr 28no dataApr 19no data
2008May 15Oct 13May 3Oct 14
2007May 24Oct 8Apr 14Oct 21
2006May 11Sep 22May 11Oct 18
2005May 12Oct 6May 2Oct 24
2004May 14Sep 23May 1Oct 14
2003May 11Sep 13May 11Oct 25
2002May 24Oct 2Apr 20Oct 15
2001May 21Sep 9May 21Oct 13
2000May 13Sep 24May 12Sep 24
1999May 12Sep 28May 12Sep 29
1998Jun 6Oct 5Apr 20Nov 5
1997no dataOct 9no dataOct 13

"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.