Frost history / Window Rock Ap, AZ
Window Rock Ap, AZ: frost dates by year
Last spring and first fall frost at NOAA station USW00003029, 1999 to 2024, measured from daily minimum temperatures.
Elevation 6,739 ft, 35.657, -109.061. Download the data (JSON) · NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 31 | Sep 23 |
| Earliest | Apr 30 (2009) | Sep 9 (2001) |
| Latest | Jun 24 (2023) | Oct 13 (2022) |
| Trend | 2.0 days later per decade | 2.7 days later per decade |
| Years with data | 25 | 26 |
At 28°F (hard freeze) the median last spring date is May 15 and the median first fall date is Oct 7.
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 27 | Sep 22 | May 11 | Oct 21 |
| 2023 | Jun 24 | Sep 25 | May 10 | Oct 5 |
| 2022 | Jun 1 | Oct 13 | May 13 | Oct 24 |
| 2021 | May 28 | Sep 21 | May 24 | Oct 11 |
| 2020 | Jun 10 | Sep 11 | Jun 9 | Sep 29 |
| 2019 | Jun 24 | Sep 22 | May 24 | Oct 7 |
| 2018 | May 5 | Sep 27 | Apr 22 | Nov 2 |
| 2017 | Jun 14 | Sep 24 | May 20 | Sep 24 |
| 2016 | May 19 | Sep 16 | Apr 29 | Oct 7 |
| 2015 | May 23 | Oct 13 | May 11 | Oct 28 |
| 2014 | May 20 | Oct 2 | May 15 | Oct 13 |
| 2013 | Jun 1 | Sep 23 | May 21 | Sep 28 |
| 2012 | May 29 | Oct 3 | May 28 | Oct 8 |
| 2011 | Jun 4 | Oct 7 | May 31 | Oct 9 |
| 2010 | no data | Sep 11 | no data | Oct 25 |
| 2009 | Apr 30 | Sep 22 | Apr 27 | Sep 23 |
| 2008 | Jun 13 | Oct 1 | Jun 12 | Oct 7 |
| 2007 | Jun 8 | Sep 25 | May 7 | Oct 7 |
| 2006 | May 31 | Sep 17 | May 29 | Sep 18 |
| 2005 | Jun 5 | Sep 15 | May 12 | Sep 18 |
| 2004 | May 31 | Sep 22 | May 14 | Oct 14 |
| 2003 | May 16 | Sep 19 | May 12 | Oct 14 |
| 2002 | May 25 | Sep 20 | May 23 | Oct 4 |
| 2001 | Jun 15 | Sep 9 | Jun 15 | Sep 9 |
| 2000 | May 21 | Sep 24 | May 14 | Sep 25 |
| 1999 | Jun 7 | Sep 28 | Jun 5 | Sep 29 |
"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 1991–2020 frost probabilities.