Frost history / San Carlos Reservoir, AZ
San Carlos Reservoir, AZ: frost dates by year
Last spring and first fall frost at NOAA station USC00027480, 1951 to 2019, measured from daily minimum temperatures.
Elevation 2,532 ft, 33.182, -110.526. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Mar 5 | Nov 26 |
| Earliest | Jan 21 (1968) | Oct 30 (1971) |
| Latest | Apr 17 (1976) | Dec 29 (1969) |
| Trend | 2.6 days earlier per decade | 0.5 days later per decade |
| Years with data | 54 | 54 |
At 28°F (hard freeze) the median last spring date is Feb 13 and the median first fall date is Dec 10.
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 |
|---|---|---|---|---|
| 2019 | Mar 14 | no data | Feb 21 | no data |
| 2018 | Mar 1 | Nov 16 | Feb 21 | Dec 14 |
| 2017 | no data | Dec 9 | no data | Dec 22 |
| 2016 | Feb 17 | Nov 24 | Feb 14 | Nov 24 |
| 2015 | Feb 2 | Nov 7 | Jan 27 | Nov 11 |
| 2014 | Jan 21 | Nov 18 | none | Nov 18 |
| 2013 | no data | Dec 6 | no data | none |
| 2011 | Feb 21 | no data | Feb 20 | no data |
| 2010 | Feb 24 | no data | Feb 23 | no data |
| 2003 | no data | Nov 24 | no data | Nov 24 |
| 2002 | Mar 16 | Dec 19 | Mar 5 | Dec 20 |
| 1998 | Mar 8 | no data | Jan 10 | no data |
| 1997 | Mar 2 | Dec 4 | Feb 7 | Dec 12 |
| 1996 | no data | Dec 1 | no data | Dec 19 |
| 1995 | Mar 26 | Dec 19 | Jan 20 | Dec 23 |
| 1994 | Feb 24 | Nov 18 | Feb 3 | Nov 20 |
| 1993 | Feb 26 | Nov 26 | Jan 5 | Nov 27 |
| 1992 | Jan 25 | Nov 12 | Jan 18 | Nov 24 |
| 1991 | Mar 28 | Nov 26 | none | Dec 2 |
| 1990 | Feb 18 | Nov 27 | Feb 18 | Dec 23 |
| 1989 | no data | Dec 1 | no data | Dec 12 |
| 1988 | Mar 14 | no data | Mar 12 | no data |
| 1987 | Mar 1 | Nov 29 | Jan 23 | Dec 14 |
| 1986 | Feb 11 | Dec 3 | Feb 11 | Dec 12 |
| 1985 | Mar 5 | Nov 16 | Feb 7 | none |
| 1984 | Feb 22 | Nov 27 | Jan 20 | none |
| 1983 | Apr 5 | Nov 24 | none | Dec 6 |
| 1982 | Feb 5 | Dec 3 | Feb 3 | Dec 27 |
| 1981 | Feb 8 | Dec 18 | none | Dec 24 |
| 1980 | Feb 12 | Dec 7 | Jan 25 | none |
| 1979 | Feb 8 | Nov 21 | Feb 6 | Nov 21 |
| 1978 | Feb 20 | Nov 19 | Jan 25 | Dec 7 |
| 1977 | Apr 4 | Dec 7 | Feb 28 | none |
| 1976 | Apr 17 | Nov 14 | Mar 6 | Nov 28 |
| 1975 | Mar 29 | Nov 19 | Mar 16 | Nov 29 |
| 1974 | Mar 10 | Oct 30 | Feb 9 | Nov 4 |
| 1973 | Feb 3 | Nov 27 | Jan 26 | none |
| 1972 | Feb 15 | Dec 6 | Feb 14 | Dec 13 |
| 1971 | Mar 9 | Oct 30 | Mar 4 | Dec 10 |
| 1970 | Feb 25 | Nov 17 | Jan 31 | Dec 12 |
| 1969 | Mar 16 | Dec 29 | Feb 1 | Dec 31 |
| 1968 | Jan 21 | Dec 4 | Jan 2 | Dec 19 |
| 1967 | Mar 9 | Dec 10 | Jan 11 | none |
| 1966 | Mar 6 | Dec 10 | Mar 5 | Dec 28 |
| 1965 | Mar 7 | Nov 29 | Feb 15 | none |
| 1964 | Mar 24 | Nov 16 | Mar 10 | Dec 14 |
| 1963 | Mar 6 | Dec 5 | Feb 14 | Dec 15 |
| 1962 | Mar 16 | Dec 23 | Mar 1 | none |
| 1961 | Feb 28 | Nov 19 | Feb 25 | none |
| 1960 | Feb 27 | Nov 17 | Feb 26 | Nov 28 |
| 1959 | Mar 7 | Nov 27 | Jan 22 | none |
| 1958 | Mar 10 | Nov 17 | Jan 25 | Nov 18 |
| 1957 | Feb 3 | Nov 23 | Jan 1 | none |
| 1956 | Mar 14 | Nov 2 | Feb 18 | Nov 4 |
| 1955 | Mar 23 | Nov 16 | Mar 22 | none |
| 1954 | Mar 14 | Dec 12 | Jan 19 | Dec 18 |
| 1953 | Mar 6 | Nov 19 | Feb 22 | Nov 20 |
| 1952 | Mar 22 | Nov 20 | Feb 21 | Nov 26 |
| 1951 | Mar 19 | Nov 19 | Mar 4 | Nov 28 |
"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.