Frost history / St Ignace Mackinac Br, MI
St Ignace Mackinac Br, MI: frost dates by year
Last spring and first fall frost at NOAA station USC00207274, 1975 to 2009, measured from daily minimum temperatures.
Elevation 595 ft, 45.849, -84.723. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 5 | Oct 11 |
| Earliest | Apr 17 (2007) | Sep 27 (1989) |
| Latest | May 28 (2008) | Nov 11 (2005) |
| Trend | 0.5 days earlier per decade | 5.4 days later per decade |
| Years with data | 29 | 28 |
At 28°F (hard freeze) the median last spring date is Apr 25 and the median first fall date is Nov 2.
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 |
|---|---|---|---|---|
| 2009 | May 12 | no data | Apr 12 | no data |
| 2008 | May 28 | Oct 28 | Apr 29 | Oct 30 |
| 2007 | Apr 17 | Nov 7 | Apr 15 | Nov 17 |
| 2006 | May 22 | Oct 12 | Apr 25 | Nov 20 |
| 2005 | May 12 | Nov 11 | Apr 24 | Nov 17 |
| 2004 | May 3 | Nov 3 | Apr 27 | Nov 8 |
| 2003 | Apr 30 | Oct 2 | Apr 26 | Nov 7 |
| 2002 | May 19 | Oct 14 | Apr 27 | Oct 16 |
| 2001 | Apr 28 | Oct 7 | Apr 17 | Oct 8 |
| 2000 | Apr 30 | Sep 28 | Apr 14 | Nov 17 |
| 1999 | Apr 24 | Oct 6 | Apr 13 | Nov 16 |
| 1998 | Apr 28 | Oct 22 | Apr 11 | Nov 4 |
| 1997 | May 22 | Oct 21 | Apr 20 | Oct 24 |
| 1996 | no data | Oct 3 | no data | Oct 31 |
| 1995 | Apr 23 | Oct 16 | Apr 20 | Nov 4 |
| 1994 | May 27 | Nov 2 | Apr 28 | Nov 2 |
| 1993 | Apr 27 | Sep 30 | Apr 26 | Oct 31 |
| 1992 | May 25 | Oct 17 | May 14 | Oct 19 |
| 1991 | May 5 | no data | Apr 12 | no data |
| 1990 | May 11 | Oct 19 | Apr 21 | Oct 26 |
| 1989 | no data | Sep 27 | no data | Nov 2 |
| 1987 | May 3 | no data | Apr 8 | no data |
| 1986 | May 4 | Oct 9 | May 2 | Nov 4 |
| 1985 | Apr 28 | Oct 11 | Apr 17 | Nov 9 |
| 1984 | no data | Oct 29 | no data | Oct 31 |
| 1983 | May 27 | no data | May 16 | no data |
| 1982 | Apr 29 | Oct 16 | Apr 28 | Nov 12 |
| 1981 | May 19 | Sep 28 | May 17 | Sep 28 |
| 1980 | Apr 26 | Oct 4 | Apr 25 | Oct 4 |
| 1979 | May 17 | Oct 10 | Apr 29 | Nov 9 |
| 1978 | no data | Oct 8 | no data | Oct 16 |
| 1977 | May 10 | no data | Apr 29 | no data |
| 1975 | May 13 | Oct 2 | Apr 22 | Oct 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.