Last Frost Day

Frost history / Orono, ME

Orono, ME: frost dates by year

Last spring and first fall frost at NOAA station USC00176430, 1952 to 2004, measured from daily minimum temperatures.

Elevation 115 ft, 44.899, -68.674. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 9Sep 28
EarliestApr 21 (1973)Aug 31 (1965)
LatestMay 27 (1997)Nov 1 (1968)
Trend1.3 days earlier per decade2.5 days later per decade
Years with data4745

At 28°F (hard freeze) the median last spring date is Apr 25 and the median first fall date is Oct 12.

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 14196019701980199020001952: May 191953: May 31954: May 131956: May 261957: May 171958: May 61962: May 131963: May 161964: May 61965: May 151966: May 141967: May 221968: Apr 301969: May 271970: May 251971: Apr 281972: May 131973: Apr 211974: May 91975: May 91976: May 11977: May 91978: May 81979: May 81980: May 51981: Apr 221982: Apr 231983: May 181984: May 191985: May 151986: May 101987: May 201988: Apr 281989: May 91990: May 251991: Apr 291992: May 271993: Apr 291994: Apr 291995: May 91996: May 71997: May 271998: Apr 291999: May 122001: Apr 292003: May 162004: Apr 29

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11196019701980199020001952: Sep 81953: Sep 231955: Sep 261956: Sep 261957: Oct 51958: Oct 41962: Sep 71963: Sep 51964: Sep 161965: Aug 311966: Sep 201967: Oct 211968: Nov 11969: Oct 161970: Oct 171971: Oct 131972: Oct 21973: Sep 221974: Sep 251975: Oct 51976: Oct 121977: Sep 221978: Sep 141979: Sep 201980: Sep 181981: Oct 101982: Oct 101983: Oct 101984: Sep 171985: Sep 121986: Sep 281987: Sep 281988: Oct 61989: Sep 251990: Oct 201991: Sep 211992: Sep 201993: Oct 11994: Oct 111995: Sep 241996: Oct 41997: Oct 31998: Oct 61999: Oct 82003: Oct 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
2004Apr 29no dataApr 25no data
2003May 16Oct 20Apr 18Oct 25
2001Apr 29no dataApr 26no data
1999May 12Oct 8Apr 16Oct 8
1998Apr 29Oct 6Apr 15Oct 6
1997May 27Oct 3Apr 27Oct 22
1996May 7Oct 4Apr 13Oct 30
1995May 9Sep 24Apr 25Oct 31
1994Apr 29Oct 11Apr 23Oct 12
1993Apr 29Oct 1Apr 28Oct 1
1992May 27Sep 20May 7Sep 24
1991Apr 29Sep 21Apr 24Oct 15
1990May 25Oct 20Apr 24Oct 21
1989May 9Sep 25Apr 29Oct 18
1988Apr 28Oct 6Apr 14Oct 7
1987May 20Sep 28May 2Oct 12
1986May 10Sep 28May 4Oct 10
1985May 15Sep 12May 15Oct 12
1984May 19Sep 17May 7Oct 6
1983May 18Oct 10Mar 31Oct 20
1982Apr 23Oct 10Apr 15Oct 23
1981Apr 22Oct 10Apr 22Oct 13
1980May 5Sep 18Apr 22Sep 25
1979May 8Sep 20Apr 21Oct 12
1978May 8Sep 14May 1Oct 11
1977May 9Sep 22Apr 11Oct 7
1976May 1Oct 12Apr 15Oct 12
1975May 9Oct 5Apr 30Oct 5
1974May 9Sep 25May 2Oct 14
1973Apr 21Sep 22Apr 15Oct 28
1972May 13Oct 2Apr 27Oct 14
1971Apr 28Oct 13Apr 15Oct 31
1970May 25Oct 17Apr 14Oct 19
1969May 27Oct 16Apr 21Oct 23
1968Apr 30Nov 1Apr 19Nov 6
1967May 22Oct 21May 7Nov 1
1966May 14Sep 20May 12Oct 14
1965May 15Aug 31May 3Sep 28
1964May 6Sep 16Apr 30Sep 19
1963May 16Sep 5May 13Sep 14
1962May 13Sep 7May 2Sep 22
1958May 6Oct 4Apr 11Oct 14
1957May 17Oct 5Apr 16Oct 28
1956May 26Sep 26May 11Oct 12
1955no dataSep 26no dataOct 23
1954May 13no dataApr 29no data
1953May 3Sep 23Apr 16Oct 9
1952May 19Sep 8May 5Oct 9

"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.