Boswell 4WNW, IN: frost dates by year

Last spring and first fall frost at NOAA station USC00120858, 1989 to 2010, measured from daily minimum temperatures.

Elevation 772 ft, 40.535, -87.453. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 24	Oct 11
Earliest	Mar 31 (1999)	Sep 20 (1991)
Latest	May 27 (1992)	Oct 28 (2007)
Trend	little change (less than half a day per decade)	9.7 days later per decade
Years with data	20	19

At 28°F (hard freeze) the median last spring date is Apr 12 and the median first fall date is Oct 15.

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
2010	Apr 28	no data	Apr 9	no data
2009	Apr 21	Oct 11	Apr 12	Oct 18
2008	no data	Oct 22	no data	Oct 28
2007	Apr 17	Oct 28	Apr 11	Oct 29
2006	Apr 27	Oct 12	Apr 10	Oct 12
2005	May 4	Oct 23	May 4	Nov 11
2004	Apr 15	no data	Apr 14	no data
2003	Apr 24	Oct 2	Apr 23	Oct 2
2002	May 21	Oct 14	Apr 7	Oct 14
2001	May 13	no data	Apr 19	no data
2000	Apr 26	Oct 7	Apr 13	Oct 7
1999	Mar 31	Oct 5	Mar 29	Oct 5
1998	Apr 18	Oct 14	Apr 5	Oct 23
1997	May 16	Oct 15	Apr 18	Oct 15
1996	Apr 27	Oct 4	Apr 17	Oct 11
1995	Apr 24	Sep 23	Apr 6	Sep 23
1994	Apr 23	Oct 11	Apr 8	Oct 27
1993	Apr 22	Sep 30	Apr 6	Sep 30
1992	May 27	Oct 17	Apr 28	Oct 19
1991	Apr 11	Sep 20	Apr 2	Oct 16
1990	Apr 18	Oct 11	Apr 18	Oct 26
1989	no data	Sep 24	no data	Oct 4

"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.