Frost history / Happy Jack Rs, AZ
Happy Jack Rs, AZ: frost dates by year
Last spring and first fall frost at NOAA station USC00023828, 1969 to 2024, measured from daily minimum temperatures.
Elevation 7,480 ft, 34.743, -111.414. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Jun 4 | Sep 28 |
| Earliest | May 8 (1973) | Sep 6 (1985) |
| Latest | Jun 22 (1977) | Oct 18 (2024) |
| Trend | 1.3 days earlier per decade | 1.4 days later per decade |
| Years with data | 25 | 28 |
At 28°F (hard freeze) the median last spring date is May 26 and the median first fall date is Oct 8.
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 |
|---|---|---|---|---|
| 2024 | May 22 | Oct 18 | May 10 | Oct 30 |
| 2019 | May 28 | Sep 22 | May 27 | Oct 11 |
| 2018 | May 26 | no data | May 3 | no data |
| 2017 | Jun 12 | Sep 22 | May 19 | Sep 23 |
| 2016 | May 27 | Oct 4 | May 27 | Oct 4 |
| 2015 | Jun 4 | Oct 3 | May 23 | Nov 1 |
| 2014 | May 25 | Sep 30 | May 12 | Nov 2 |
| 2013 | Jun 1 | Sep 23 | Jun 1 | Oct 4 |
| 2012 | May 29 | Oct 13 | May 27 | Oct 13 |
| 2011 | Jun 13 | Oct 6 | Jun 3 | Oct 6 |
| 2010 | Jun 13 | Oct 8 | May 25 | Oct 8 |
| 2009 | no data | Sep 30 | no data | Oct 1 |
| 2007 | Jun 9 | Sep 18 | May 9 | Oct 6 |
| 2006 | no data | Sep 21 | no data | Oct 11 |
| 2003 | no data | Sep 11 | no data | Sep 20 |
| 1997 | no data | Sep 23 | no data | Oct 8 |
| 1995 | Jun 20 | no data | Jun 19 | no data |
| 1994 | Jun 1 | no data | May 21 | no data |
| 1993 | Jun 9 | Sep 14 | Jun 7 | Oct 18 |
| 1985 | no data | Sep 6 | no data | Sep 12 |
| 1984 | no data | Oct 3 | no data | Oct 16 |
| 1983 | no data | Oct 3 | no data | Oct 20 |
| 1982 | Jun 14 | Sep 28 | Jun 6 | Oct 1 |
| 1981 | May 24 | Oct 4 | May 21 | Oct 15 |
| 1979 | no data | Oct 12 | no data | Oct 16 |
| 1978 | Jun 2 | no data | May 28 | no data |
| 1977 | Jun 22 | no data | May 27 | no data |
| 1976 | no data | Sep 18 | no data | Oct 11 |
| 1975 | Jun 21 | no data | May 23 | no data |
| 1974 | Jun 9 | Sep 28 | May 21 | Sep 28 |
| 1973 | May 8 | no data | May 7 | no data |
| 1972 | May 27 | Sep 20 | May 26 | Oct 22 |
| 1971 | Jun 8 | Sep 20 | Jun 6 | Sep 20 |
| 1970 | Jun 17 | Sep 15 | Jun 15 | Oct 8 |
| 1969 | no data | Oct 4 | no data | Oct 5 |
"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.