Frost history / Ajo, AZ
Ajo, AZ: frost dates by year
Last spring and first fall frost at NOAA station USC00020080, 1951 to 2025, measured from daily minimum temperatures.
Elevation 1,751 ft, 32.370, -112.860. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Feb 4 | Dec 10 |
| Earliest | Jan 3 (1974) | Oct 30 (1971) |
| Latest | Mar 14 (1954) | Dec 31 (1969) |
| Trend | 0.7 days earlier per decade | 0.7 days later per decade |
| Years with data | 51, 18 with no freeze | 49, 24 with no freeze |
At 28°F (hard freeze) the median last spring date is Jan 18 and the median first fall date is Dec 23.
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 |
|---|---|---|---|---|
| 2025 | none | none | none | none |
| 2024 | Jan 11 | none | none | none |
| 2023 | Feb 16 | none | none | none |
| 2022 | Feb 23 | Dec 17 | none | none |
| 2021 | Jan 27 | none | none | none |
| 2020 | Feb 6 | Dec 15 | none | none |
| 2019 | Feb 24 | Dec 18 | Jan 3 | none |
| 2018 | none | Dec 30 | none | Dec 30 |
| 2017 | none | none | none | none |
| 2016 | Feb 4 | none | none | none |
| 2015 | Jan 3 | Nov 30 | Jan 2 | none |
| 2014 | none | none | none | none |
| 2013 | Feb 12 | Dec 9 | Jan 15 | none |
| 2012 | Feb 28 | none | none | none |
| 2011 | Feb 4 | Dec 4 | Feb 4 | none |
| 2010 | none | Nov 30 | none | none |
| 1985 | Feb 4 | no data | Feb 4 | no data |
| 1984 | none | none | none | none |
| 1983 | none | none | none | none |
| 1982 | none | none | none | none |
| 1981 | none | none | none | none |
| 1980 | none | none | none | none |
| 1979 | Jan 30 | none | none | none |
| 1978 | none | Dec 8 | none | Dec 8 |
| 1977 | none | none | none | none |
| 1976 | Jan 3 | no data | none | no data |
| 1975 | none | none | none | none |
| 1974 | Jan 3 | Dec 24 | none | none |
| 1973 | Jan 22 | none | none | none |
| 1972 | Feb 4 | Dec 10 | Jan 6 | Dec 12 |
| 1971 | Mar 3 | Oct 30 | Mar 2 | Dec 9 |
| 1970 | Jan 7 | none | Jan 7 | none |
| 1969 | Feb 1 | Dec 31 | none | Dec 31 |
| 1968 | none | Dec 18 | none | Dec 22 |
| 1967 | Jan 10 | Dec 10 | none | none |
| 1966 | Mar 3 | Dec 28 | none | Dec 29 |
| 1965 | Mar 3 | none | Feb 13 | none |
| 1964 | Feb 15 | none | Jan 16 | none |
| 1963 | Jan 20 | Dec 13 | Jan 20 | none |
| 1962 | Mar 1 | none | Feb 28 | none |
| 1961 | none | Dec 12 | none | none |
| 1960 | Jan 19 | Dec 7 | Jan 6 | Dec 7 |
| 1959 | none | none | none | none |
| 1958 | none | Nov 17 | none | none |
| 1957 | none | none | none | none |
| 1956 | Feb 9 | Nov 20 | Feb 4 | none |
| 1955 | Feb 23 | none | Feb 21 | none |
| 1954 | Mar 14 | Dec 28 | none | Dec 28 |
| 1953 | Feb 22 | Nov 21 | none | Dec 24 |
| 1952 | Jan 9 | Dec 24 | Jan 4 | none |
| 1951 | Mar 4 | Dec 8 | 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.