Last Frost Day

Frost history / Kitt Peak, AZ

Kitt Peak, AZ: frost dates by year

Last spring and first fall frost at NOAA station USC00024675, 1961 to 2025, measured from daily minimum temperatures.

Elevation 6,790 ft, 31.960, -111.598. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 26Nov 9
EarliestMar 25 (2002)Oct 7 (1970)
LatestMay 28 (1962)Nov 29 (1967)
Trend3.7 days earlier per decade0.7 days later per decade
Years with data5044

At 28°F (hard freeze) the median last spring date is Apr 8 and the median first fall date is Nov 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)

Mar 16Mar 31Apr 15Apr 30May 15May 30Jun 141970198019902000201020201961: May 121962: May 281963: Apr 271964: May 81965: Apr 141966: Apr 201967: May 21968: Apr 241969: May 71970: Apr 301971: Apr 261972: Apr 201973: May 61974: Apr 111975: May 221976: Apr 181977: May 181978: May 71979: May 101980: Apr 301981: Apr 51982: May 121983: May 21984: Apr 301985: May 111986: Apr 41987: Apr 81988: May 51989: Apr 271990: Mar 301991: Apr 131992: Apr 31993: Mar 301994: Apr 281995: May 81997: Apr 101998: Apr 171999: May 12000: Apr 22001: Apr 222002: Mar 252003: Apr 232004: May 202005: Apr 12006: Apr 292013: Apr 182014: Apr 42015: May 112016: Mar 312025: Apr 19

First fall frost (32°F)

Sep 27Oct 12Oct 27Nov 11Nov 26Dec 111970198019902000201020201961: Oct 291962: Nov 171963: Nov 71964: Nov 111965: Nov 261966: Nov 91967: Nov 291968: Nov 141969: Nov 91970: Oct 71971: Oct 171972: Oct 211973: Nov 191974: Oct 291975: Nov 191976: Oct 281977: Nov 71978: Nov 131979: Oct 301980: Oct 161981: Oct 161982: Nov 111983: Nov 191984: Nov 181985: Nov 121986: Nov 61987: Nov 151988: Nov 151989: Nov 281991: Oct 281992: Nov 41993: Nov 131994: Oct 171996: Oct 211997: Oct 251998: Nov 101999: Nov 222000: Oct 312001: Nov 252002: Nov 62003: Oct 262015: Nov 52019: Nov 212025: Nov 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
2025Apr 19Nov 20Apr 4Dec 4
2019no dataNov 21no dataNov 29
2016Mar 31no dataMar 30no data
2015May 11Nov 5Jan 22Nov 17
2014Apr 4no dataApr 4no data
2013Apr 18no dataApr 9no data
2006Apr 29no dataApr 6no data
2005Apr 1no dataMar 16no data
2004May 20no dataMay 13no data
2003Apr 23Oct 26Apr 6Oct 26
2002Mar 25Nov 6Mar 20Dec 18
2001Apr 22Nov 25Apr 22Nov 26
2000Apr 2Oct 31Mar 22Nov 7
1999May 1Nov 22Apr 30Nov 23
1998Apr 17Nov 10Apr 16Nov 10
1997Apr 10Oct 25Apr 5Dec 2
1996no dataOct 21no dataOct 27
1995May 8no dataMay 7no data
1994Apr 28Oct 17Apr 27Oct 17
1993Mar 30Nov 13Mar 29Nov 13
1992Apr 3Nov 4Apr 2Nov 4
1991Apr 13Oct 28Apr 12Oct 31
1990Mar 30no dataMar 15no data
1989Apr 27Nov 28Mar 27Nov 29
1988May 5Nov 15Apr 17Nov 15
1987Apr 8Nov 15Apr 6Nov 15
1986Apr 4Nov 6Mar 18Dec 9
1985May 11Nov 12Apr 1Nov 14
1984Apr 30Nov 18Apr 29Nov 18
1983May 2Nov 19Apr 14Nov 19
1982May 12Nov 11Apr 2Nov 11
1981Apr 5Oct 16Apr 5Nov 26
1980Apr 30Oct 16Apr 24Nov 17
1979May 10Oct 30Mar 30Oct 30
1978May 7Nov 13Apr 9Nov 15
1977May 18Nov 7May 14Nov 7
1976Apr 18Oct 28Apr 18Nov 14
1975May 22Nov 19Apr 27Nov 19
1974Apr 11Oct 29Apr 10Oct 30
1973May 6Nov 19Apr 9Nov 19
1972Apr 20Oct 21Apr 14Oct 31
1971Apr 26Oct 17Apr 22Oct 19
1970Apr 30Oct 7Apr 29Oct 28
1969May 7Nov 9May 6Nov 18
1968Apr 24Nov 14Apr 19Nov 27
1967May 2Nov 29Apr 30Nov 29
1966Apr 20Nov 9Mar 5Nov 26
1965Apr 14Nov 26Apr 12Nov 26
1964May 8Nov 11Apr 8Nov 15
1963Apr 27Nov 7Apr 2Nov 8
1962May 28Nov 17Mar 24Nov 19
1961May 12Oct 29Mar 29Oct 29

"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.