Frost history / Byron 4NORTH, MN
Byron 4NORTH, MN: frost dates by year
Last spring and first fall frost at NOAA station USC00211174, 1993 to 2017, measured from daily minimum temperatures.
Elevation 1,041 ft, 44.091, -92.640. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 16 | Sep 23 |
| Earliest | Apr 27 (2012) | Sep 13 (1996) |
| Latest | May 27 (1997) | Oct 16 (2017) |
| Trend | 2.5 days earlier per decade | 5.6 days later per decade |
| Years with data | 14 | 14 |
At 28°F (hard freeze) the median last spring date is May 2 and the median first fall date is Oct 5.
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 |
|---|---|---|---|---|
| 2017 | May 3 | Oct 16 | Apr 28 | Oct 29 |
| 2016 | May 18 | Oct 8 | May 15 | Oct 13 |
| 2015 | May 13 | Sep 30 | Apr 27 | Oct 17 |
| 2014 | May 14 | Sep 13 | Apr 25 | Oct 10 |
| 2013 | May 24 | Oct 13 | May 13 | Oct 17 |
| 2012 | Apr 27 | Sep 23 | Apr 21 | Sep 23 |
| 2011 | May 17 | Sep 15 | May 4 | Sep 15 |
| 2010 | May 10 | Oct 3 | May 9 | Oct 3 |
| 2008 | May 21 | no data | Apr 30 | no data |
| 2007 | May 18 | Sep 15 | Apr 16 | Sep 15 |
| 2006 | May 22 | no data | Apr 26 | no data |
| 1999 | no data | Sep 21 | no data | Sep 21 |
| 1998 | no data | Oct 1 | no data | Oct 8 |
| 1997 | May 27 | Sep 21 | May 21 | Oct 15 |
| 1996 | May 13 | Sep 13 | May 13 | Sep 14 |
| 1994 | May 10 | no data | May 6 | no data |
| 1993 | no data | Sep 24 | no data | Sep 30 |
"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.