Frost history / St Johns Industrial Ap, AZ
St Johns Industrial Ap, AZ: frost dates by year
Last spring and first fall frost at NOAA station USW00093027, 1999 to 2021, measured from daily minimum temperatures.
Elevation 5,733 ft, 34.518, -109.379. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 6 | Oct 14 |
| Earliest | Apr 19 (2004) | Sep 23 (2009) |
| Latest | Jun 9 (2020) | Nov 3 (2014) |
| Trend | 10.9 days later per decade | 2.2 days later per decade |
| Years with data | 22 | 23 |
At 28°F (hard freeze) the median last spring date is Apr 18 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 |
|---|---|---|---|---|
| 2021 | May 23 | Oct 11 | Apr 19 | Oct 15 |
| 2020 | Jun 9 | Oct 26 | Apr 10 | Oct 27 |
| 2019 | May 24 | Oct 10 | Apr 13 | Oct 11 |
| 2018 | May 4 | Oct 19 | Apr 18 | Nov 4 |
| 2017 | May 20 | Sep 25 | Apr 11 | Oct 10 |
| 2016 | May 2 | Oct 20 | Apr 26 | Oct 20 |
| 2015 | Apr 29 | Oct 31 | Apr 16 | Nov 6 |
| 2014 | May 15 | Nov 3 | Apr 30 | Nov 5 |
| 2013 | May 3 | Sep 28 | Apr 19 | Oct 6 |
| 2012 | May 27 | Oct 14 | Apr 7 | Oct 26 |
| 2011 | May 19 | Oct 8 | May 3 | Nov 2 |
| 2010 | May 12 | Oct 26 | Apr 23 | Oct 28 |
| 2009 | Apr 20 | Sep 23 | Apr 17 | Oct 2 |
| 2008 | May 4 | Oct 12 | May 3 | Oct 13 |
| 2007 | May 7 | Oct 7 | Apr 14 | Oct 22 |
| 2006 | Apr 19 | Oct 19 | Mar 24 | Nov 2 |
| 2005 | Apr 22 | Oct 31 | Apr 2 | Nov 1 |
| 2004 | Apr 19 | Oct 14 | Mar 7 | Oct 23 |
| 2003 | May 11 | Oct 26 | May 11 | Oct 26 |
| 2002 | May 2 | Oct 4 | Apr 22 | Nov 5 |
| 2001 | May 4 | Oct 11 | Apr 24 | Nov 14 |
| 2000 | May 13 | Sep 25 | May 13 | Nov 2 |
| 1999 | no data | Oct 17 | no data | Oct 17 |
"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.