Last Frost Day

Frost history / Colebrook 3SW, NH

Colebrook 3SW, NH: frost dates by year

Last spring and first fall frost at NOAA station USC00271647, 1960 to 2025, measured from daily minimum temperatures.

Elevation 1,120 ft, 44.861, -71.539. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 3Sep 15
EarliestApr 28 (2024)Aug 3 (1976)
LatestJul 15 (1989)Oct 24 (2023)
Trend4.8 days earlier per decade5.6 days later per decade
Years with data5956

At 28°F (hard freeze) the median last spring date is May 18 and the median first fall date is Oct 3.

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)

Apr 15Apr 30May 15May 30Jun 14Jun 29Jul 14Jul 2919601970198019902000201020201961: Jun 151962: Jul 31964: Jun 61965: Jun 31968: May 291969: Jul 91970: Jun 261971: Jun 121972: Jun 121973: Jun 181974: May 211975: Jun 101976: Jun 131977: May 301978: Jul 31979: Jun 261980: Jun 91981: Jun 81982: Jul 51984: Jun 161985: May 301986: Jun 31987: Jun 71988: Jun 91989: Jul 151990: Jun 61991: May 231992: Jul 21993: Jun 51994: Jun 101996: May 281997: May 281998: May 271999: May 212000: May 202001: Jun 12002: Jun 42003: May 222004: Jun 122005: May 252007: Jun 72008: May 302009: May 272010: May 182011: May 152012: May 182013: May 282014: May 202015: Jun 72016: May 182017: May 212018: Jun 122019: Jun 12020: Jun 32021: May 302022: May 252023: May 272024: Apr 282025: May 15

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201960: Sep 31961: Sep 171963: Sep 141964: Sep 131968: Aug 161969: Aug 231970: Sep 31971: Aug 251972: Aug 51973: Sep 171974: Sep 151975: Sep 111976: Aug 31977: Sep 81978: Aug 251979: Aug 171980: Sep 81981: Sep 101983: Sep 141984: Sep 61985: Sep 121986: Aug 291987: Aug 261988: Sep 151989: Aug 251990: Sep 81991: Sep 131992: Sep 241993: Sep 201995: Sep 111996: Sep 241997: Sep 221998: Sep 241999: Sep 192000: Sep 52001: Sep 152002: Sep 292003: Oct 22004: Oct 32005: Sep 242010: Sep 212011: Sep 172012: Sep 172013: Sep 92014: Sep 162015: Sep 262016: Sep 252017: Oct 12018: Sep 232019: Sep 192020: Sep 152021: Oct 242022: Sep 302023: Oct 242024: Oct 132025: Sep 20

Dots are single years. The gray line is the median, the green line the fitted trend.

Year by year

YearLast spring 32°FFirst fall 32°FLast spring 28°FFirst fall 28°F
2025May 15Sep 20May 2Sep 21
2024Apr 28Oct 13Apr 28Oct 14
2023May 27Oct 24May 27Oct 31
2022May 25Sep 30May 10Oct 3
2021May 30Oct 24May 7Oct 25
2020Jun 3Sep 15May 14Sep 19
2019Jun 1Sep 19May 10Oct 5
2018Jun 12Sep 23May 18Oct 15
2017May 21Oct 1May 10Oct 13
2016May 18Sep 25May 17Oct 10
2015Jun 7Sep 26May 21Oct 3
2014May 20Sep 16May 9Sep 19
2013May 28Sep 9May 15Oct 21
2012May 18Sep 17May 12Oct 9
2011May 15Sep 17May 1Oct 7
2010May 18Sep 21May 17Oct 10
2009May 27no dataMay 26no data
2008May 30no dataMay 3no data
2007Jun 7no dataMay 22no data
2005May 25Sep 24May 14Oct 21
2004Jun 12Oct 3May 8Oct 6
2003May 22Oct 2May 5Oct 7
2002Jun 4Sep 29May 20Oct 8
2001Jun 1Sep 15May 14Oct 9
2000May 20Sep 5May 20Sep 29
1999May 21Sep 19May 13Oct 8
1998May 27Sep 24Apr 29Oct 4
1997May 28Sep 22May 28Oct 8
1996May 28Sep 24May 27Oct 4
1995no dataSep 11no dataSep 29
1994Jun 10no dataMay 15no data
1993Jun 5Sep 20May 14Sep 20
1992Jul 2Sep 24May 25Sep 24
1991May 23Sep 13May 19Oct 14
1990Jun 6Sep 8May 25Oct 20
1989Jul 15Aug 25May 10Sep 25
1988Jun 9Sep 15May 15Sep 25
1987Jun 7Aug 26May 16Sep 27
1986Jun 3Aug 29Jun 3Sep 28
1985May 30Sep 12May 15Oct 18
1984Jun 16Sep 6May 19Sep 27
1983no dataSep 14no dataSep 15
1982Jul 5no dataJun 4no data
1981Jun 8Sep 10May 24Oct 5
1980Jun 9Sep 8May 30Sep 9
1979Jun 26Aug 17Jun 26Sep 20
1978Jul 3Aug 25May 23Sep 13
1977May 30Sep 8May 16Oct 5
1976Jun 13Aug 3May 14Sep 25
1975Jun 10Sep 11May 10Sep 15
1974May 21Sep 15May 21Sep 24
1973Jun 18Sep 17Jun 3Sep 21
1972Jun 12Aug 5May 26Sep 21
1971Jun 12Aug 25Jun 11Sep 25
1970Jun 26Sep 3Jun 26Sep 3
1969Jul 9Aug 23May 27Sep 21
1968May 29Aug 16May 28Oct 6
1965Jun 3no dataMay 24no data
1964Jun 6Sep 13May 21Sep 13
1963no dataSep 14no dataSep 14
1962Jul 3no dataMay 28no data
1961Jun 15Sep 17May 31Sep 30
1960no dataSep 3no dataOct 2

"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.