Last Frost Day

Frost history / Malta 4 Ese, ID

Malta 4 Ese, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00105563, 1965 to 2002, measured from daily minimum temperatures.

Elevation 4,590 ft, 42.292, -113.304. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 13Sep 12
EarliestMay 4 (1987)Aug 18 (1978)
LatestJul 8 (1981)Oct 7 (1990)
Trendlittle change (less than half a day per decade)1.9 days later per decade
Years with data3533

At 28°F (hard freeze) the median last spring date is May 16 and the median first fall date is Sep 22.

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 1419701980199020001965: Jun 181966: Jul 31967: May 311971: May 191972: May 271973: Jun 191974: Jun 81975: Jun 191976: Jun 151977: May 291978: Jun 11979: Jun 91980: Jun 151981: Jul 81982: Jun 91983: May 201984: Jun 121985: Jun 261986: Jul 61987: May 41988: Jun 301989: Jun 211990: Jun 131991: Jun 151992: Jun 131993: Jun 131994: May 211995: Jun 71996: May 231997: Jun 241998: Jun 51999: Jun 262000: Jun 12001: Jun 192002: Jun 11

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 1219701980199020001965: Aug 291970: Sep 101971: Sep 41972: Sep 121973: Sep 261974: Sep 121975: Sep 181976: Sep 81977: Sep 91978: Aug 181979: Sep 111980: Sep 221981: Sep 201982: Sep 111983: Sep 101984: Sep 141985: Sep 101986: Sep 151987: Sep 171988: Sep 191989: Sep 101990: Oct 71991: Sep 151992: Aug 241993: Aug 261994: Sep 221995: Sep 211996: Aug 191997: Sep 281998: Oct 51999: Sep 12000: Sep 232001: Sep 7

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
2002Jun 11no dataJun 10no data
2001Jun 19Sep 7May 21Sep 8
2000Jun 1Sep 23Jun 1Sep 23
1999Jun 26Sep 1May 16Sep 27
1998Jun 5Oct 5Apr 27Oct 5
1997Jun 24Sep 28May 2Oct 6
1996May 23Aug 19Apr 29Sep 18
1995Jun 7Sep 21Jun 7Sep 21
1994May 21Sep 22Apr 29Oct 23
1993Jun 13Aug 26Jun 13Sep 14
1992Jun 13Aug 24May 2Aug 25
1991Jun 15Sep 15May 1Sep 22
1990Jun 13Oct 7May 16Oct 7
1989Jun 21Sep 10May 26Sep 11
1988Jun 30Sep 19Jun 7Oct 23
1987May 4Sep 17Apr 20Sep 17
1986Jul 6Sep 15May 23Sep 22
1985Jun 26Sep 10May 13Sep 25
1984Jun 12Sep 14May 7Sep 22
1983May 20Sep 10May 14Sep 20
1982Jun 9Sep 11May 31Oct 6
1981Jul 8Sep 20May 13Sep 23
1980Jun 15Sep 22Apr 16Sep 22
1979Jun 9Sep 11Jun 8Sep 11
1978Jun 1Aug 18Jun 1Sep 20
1977May 29Sep 9May 5Oct 4
1976Jun 15Sep 8May 1Sep 8
1975Jun 19Sep 18May 26Sep 19
1974Jun 8Sep 12May 31Sep 13
1973Jun 19Sep 26May 11Oct 3
1972May 27Sep 12May 9Sep 25
1971May 19Sep 4May 18Sep 18
1970no dataSep 10no dataSep 14
1967May 31no dataMay 26no data
1966Jul 3no dataJun 23no data
1965Jun 18Aug 29May 11Aug 31

"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.