Frost history / Colorado City, AZ
Colorado City, AZ: frost dates by year
Last spring and first fall frost at NOAA station USC00021920, 1965 to 2011, measured from daily minimum temperatures.
Elevation 5,001 ft, 36.994, -112.972. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 5 | Oct 16 |
| Earliest | Mar 24 (1992) | Sep 19 (1978) |
| Latest | Jun 5 (1999) | Nov 12 (1988) |
| Trend | 1.0 days earlier per decade | 2.4 days later per decade |
| Years with data | 41 | 41 |
At 28°F (hard freeze) the median last spring date is Apr 20 and the median first fall date is Oct 26.
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 |
|---|---|---|---|---|
| 2011 | Apr 30 | Oct 7 | Apr 30 | Oct 8 |
| 2010 | May 26 | Oct 26 | May 26 | Oct 26 |
| 2009 | Apr 29 | Oct 2 | Apr 29 | Oct 5 |
| 2008 | May 14 | no data | May 2 | no data |
| 2007 | Apr 22 | no data | Apr 19 | no data |
| 2006 | Apr 25 | Oct 18 | Mar 31 | Oct 19 |
| 2005 | May 12 | Nov 5 | Apr 6 | Nov 7 |
| 2003 | no data | Nov 4 | no data | Nov 22 |
| 1999 | Jun 5 | Oct 16 | Jun 5 | Oct 18 |
| 1998 | Apr 18 | Oct 17 | Apr 17 | Oct 17 |
| 1997 | Apr 14 | Oct 13 | Apr 6 | Oct 25 |
| 1996 | Apr 20 | Oct 20 | Apr 19 | Oct 20 |
| 1995 | May 7 | Oct 25 | Apr 11 | Nov 27 |
| 1994 | Apr 29 | Oct 16 | Apr 25 | Oct 16 |
| 1993 | May 5 | Oct 19 | Apr 13 | Nov 2 |
| 1992 | Mar 24 | Nov 1 | Mar 18 | Nov 4 |
| 1991 | May 19 | Oct 28 | Apr 29 | Oct 28 |
| 1990 | Apr 5 | Oct 8 | Apr 5 | Nov 3 |
| 1989 | Apr 28 | Oct 26 | Apr 27 | Oct 28 |
| 1988 | May 8 | Nov 12 | May 4 | Nov 15 |
| 1987 | Apr 20 | Nov 12 | Apr 20 | Nov 16 |
| 1986 | May 9 | Oct 12 | Apr 27 | Nov 7 |
| 1985 | May 13 | Oct 11 | Mar 31 | Oct 22 |
| 1984 | Apr 30 | Oct 15 | Apr 29 | Oct 16 |
| 1983 | May 17 | Nov 9 | Apr 14 | Nov 9 |
| 1982 | May 12 | Oct 8 | Apr 8 | Oct 9 |
| 1981 | Apr 4 | Oct 13 | Apr 4 | Oct 30 |
| 1980 | May 25 | Oct 16 | Apr 3 | Oct 23 |
| 1979 | May 10 | Oct 30 | Apr 11 | Oct 30 |
| 1978 | May 7 | Sep 19 | Apr 17 | Nov 15 |
| 1977 | May 18 | Nov 1 | Apr 4 | Nov 8 |
| 1976 | Apr 27 | Oct 20 | Apr 26 | Oct 20 |
| 1975 | May 7 | Oct 8 | May 7 | Oct 14 |
| 1974 | May 20 | Oct 29 | Apr 27 | Nov 11 |
| 1973 | May 2 | Oct 10 | Apr 21 | Oct 10 |
| 1972 | May 21 | Oct 30 | Apr 20 | Oct 30 |
| 1971 | May 23 | Oct 1 | Apr 27 | Oct 1 |
| 1970 | May 1 | Oct 8 | May 1 | Oct 8 |
| 1969 | Apr 26 | Oct 4 | Apr 26 | Oct 4 |
| 1968 | Apr 27 | Oct 16 | Apr 23 | Oct 16 |
| 1967 | May 14 | Oct 17 | May 13 | Nov 24 |
| 1966 | Apr 22 | Oct 14 | Apr 20 | Oct 14 |
| 1965 | no data | Sep 20 | no data | Nov 26 |
"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.