Photos of the Long Island Sound

Research & Monitoring

ATTENTION!!

The Long Island Sound Study has launched a new version of the Environmental Indicators section. The data below may be out of date. Please visit and bookmark the new section here to see the most recent data.

Status and Trends: LISS Environmental Indicators

First and Last Frost indicator
first frost day in fall last frost day in spring
1973 292 111
1974 267 128
1975 281 128
1976 273 130
1977 297 130
1978 269 127
1979 na na
1980 na na
1981 na na
1982 na na
1983 na na
1984 na na
1985 286 124
1986 na na
1987 278 119
1988 282 117
1989 na na
1990 300 109
1991 265 111
1992 275 128
1993 274 118
1994 na na
1995 291 108
1996 278 136
1997 296 128
1998 307 134
1999 279 138
2000 na na
2001 na na
2002 na na
2003 na na
2004 280 151
2005 295 133
2006 287 121
2007 302 134
2008 281 122
2009 275 114
2010 283 133
2011 279 122
2012 287 121
2013 294 135
2014 279 117
2015 284 122

Loomis and Newton (1866) also examined the data they assembled to assess whether there had been appreciable change in the date of the last frost of spring or the first frost of fall. Since the records of the occurrence of frost were unreliable, they instead examined trends in the last day in spring that 40F (4.4 C) was recorded and the first day after the start of fall when the temperature fell below the threshold. They averaged the number of the day of the year from 1779-1820 (series 1) and 1820-1865 (series 2) and found that day 140.2 (May 19th) was the average last frost in the first series and 140.9 was the average in the later series. The first frost of fall occurred on average in day 266.2 (September 22nd) in the first series and 264.4 in the second series. These dates are represented in Figure 3.3 by the red (last frost) and blue (first frost) lines. The dashed
lines show the means from the first range of years.

Show/Hide Table

Subscribe to receive our e-newsletter, Sound Bytes by providing your email address. Interested in a free copy of our print newsletter, Sound Update? Then also provide your home/company/school address.