Frost history / Superior, AZ
Superior, AZ: frost dates by year
Last spring and first fall frost at NOAA station USC00028348, 1954 to 2006, measured from daily minimum temperatures.
Elevation 2,860 ft, 33.300, -111.097. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Feb 11 | Dec 11 |
| Earliest | Jan 4 (2000) | Nov 16 (1964) |
| Latest | Apr 16 (1976) | Dec 29 (1969) |
| Trend | little change (less than half a day per decade) | 0.7 days earlier per decade |
| Years with data | 46, 12 with no freeze | 44, 17 with no freeze |
At 28°F (hard freeze) the median last spring date is Feb 3 and the median first fall date is Dec 22.
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 |
|---|---|---|---|---|
| 2006 | Mar 12 | no data | none | no data |
| 2004 | no data | Nov 29 | no data | none |
| 2003 | none | Dec 15 | none | Dec 28 |
| 2002 | Feb 1 | none | none | none |
| 2001 | Apr 11 | Dec 13 | none | none |
| 2000 | Jan 4 | none | none | none |
| 1999 | Apr 5 | none | none | none |
| 1997 | Mar 1 | no data | Jan 9 | no data |
| 1996 | Jan 23 | no data | none | no data |
| 1995 | Jan 17 | none | none | none |
| 1994 | none | Nov 20 | none | none |
| 1993 | none | no data | none | no data |
| 1992 | none | none | none | none |
| 1991 | Mar 28 | Dec 1 | none | none |
| 1990 | Mar 14 | Dec 22 | Feb 16 | Dec 22 |
| 1989 | Feb 7 | none | none | none |
| 1988 | Jan 31 | Dec 27 | Jan 25 | Dec 29 |
| 1987 | no data | Dec 1 | no data | Dec 1 |
| 1986 | Feb 6 | none | none | none |
| 1985 | Feb 6 | Dec 12 | Feb 6 | none |
| 1984 | none | Nov 26 | none | Dec 9 |
| 1983 | Jan 26 | Nov 26 | none | none |
| 1982 | no data | Dec 3 | no data | none |
| 1979 | Jan 31 | none | Jan 31 | none |
| 1978 | Feb 10 | no data | none | no data |
| 1977 | Jan 9 | none | none | none |
| 1976 | Apr 16 | Nov 28 | none | none |
| 1975 | Mar 17 | none | Feb 21 | none |
| 1974 | none | Dec 24 | none | Dec 24 |
| 1973 | Jan 23 | none | none | none |
| 1972 | Jan 5 | Dec 11 | none | none |
| 1971 | Mar 3 | Dec 9 | Mar 3 | none |
| 1970 | Jan 5 | none | none | none |
| 1969 | Jan 30 | Dec 29 | none | none |
| 1968 | none | Dec 18 | none | Dec 21 |
| 1967 | Apr 14 | Dec 14 | none | none |
| 1966 | Mar 5 | Dec 27 | Mar 5 | Dec 31 |
| 1965 | Feb 13 | Dec 24 | none | none |
| 1964 | Mar 5 | Nov 16 | none | none |
| 1963 | Jan 21 | none | Jan 21 | none |
| 1962 | Mar 11 | none | Jan 12 | none |
| 1961 | none | none | none | none |
| 1960 | Feb 25 | Dec 6 | Jan 18 | Dec 7 |
| 1959 | none | Dec 14 | none | none |
| 1958 | none | Nov 17 | none | none |
| 1957 | none | none | none | none |
| 1956 | Feb 18 | Nov 20 | Feb 3 | none |
| 1955 | Mar 21 | none | Feb 21 | none |
| 1954 | none | Dec 27 | none | none |
"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.