Frost history / Sunburst 8 E, MT
Sunburst 8 E, MT: frost dates by year
Last spring and first fall frost at NOAA station USC00247996, 1980 to 2013, measured from daily minimum temperatures.
Elevation 3,700 ft, 48.887, -111.728. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 21 | Sep 19 |
| Earliest | May 3 (2013) | Aug 25 (1980) |
| Latest | Jun 13 (1991) | Oct 9 (2008) |
| Trend | little change (less than half a day per decade) | 2.7 days later per decade |
| Years with data | 30 | 27 |
At 28°F (hard freeze) the median last spring date is May 8 and the median first fall date is Oct 6.
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 |
|---|---|---|---|---|
| 2013 | May 3 | Sep 27 | May 3 | Oct 4 |
| 2012 | May 27 | no data | May 11 | no data |
| 2011 | May 30 | Sep 3 | May 1 | Oct 17 |
| 2010 | Jun 3 | Sep 17 | May 10 | Oct 16 |
| 2009 | Jun 6 | Sep 26 | May 15 | Oct 6 |
| 2008 | May 25 | Oct 9 | May 25 | Oct 9 |
| 2007 | May 6 | Sep 14 | Apr 21 | Oct 26 |
| 2006 | May 10 | Sep 18 | May 4 | Oct 7 |
| 2005 | May 12 | Sep 24 | May 11 | Oct 31 |
| 2004 | May 24 | Sep 10 | May 13 | Oct 1 |
| 2003 | May 19 | Sep 16 | May 18 | Sep 17 |
| 2002 | Jun 10 | Sep 23 | May 23 | Oct 2 |
| 2001 | May 20 | Oct 2 | May 20 | Oct 5 |
| 2000 | May 14 | Sep 20 | May 7 | Sep 21 |
| 1999 | May 14 | Sep 27 | May 11 | Sep 28 |
| 1998 | Jun 2 | Oct 4 | Apr 18 | Oct 11 |
| 1997 | May 19 | Sep 19 | Apr 24 | Oct 8 |
| 1993 | May 27 | no data | Apr 28 | no data |
| 1992 | May 22 | no data | May 16 | no data |
| 1991 | Jun 13 | no data | May 3 | no data |
| 1990 | May 16 | Sep 28 | May 16 | Oct 6 |
| 1989 | Jun 10 | Sep 10 | May 17 | Sep 10 |
| 1988 | May 4 | Sep 8 | Apr 27 | Oct 18 |
| 1987 | May 22 | Oct 6 | Apr 20 | Oct 9 |
| 1986 | May 17 | Sep 6 | May 17 | Oct 11 |
| 1985 | May 13 | Sep 6 | Apr 22 | Sep 23 |
| 1984 | May 22 | Sep 22 | May 5 | Sep 23 |
| 1983 | May 13 | Sep 10 | May 13 | Sep 18 |
| 1982 | Jun 8 | Sep 13 | May 6 | Sep 13 |
| 1981 | May 12 | Oct 3 | May 3 | Oct 4 |
| 1980 | no data | Aug 25 | no data | Oct 10 |
"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.