Last Frost Day

Frost history / Duncan, AZ

Duncan, AZ: frost dates by year

Last spring and first fall frost at NOAA station USC00022754, 1951 to 2025, measured from daily minimum temperatures.

Elevation 3,660 ft, 32.748, -109.121. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 29Oct 23
EarliestMar 7 (2004)Oct 2 (1982)
LatestMay 26 (1980)Nov 20 (2001)
Trend1.1 days earlier per decade1.0 days later per decade
Years with data7271

At 28°F (hard freeze) the median last spring date is Apr 16 and the median first fall date is Nov 2.

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 1Mar 16Mar 31Apr 15Apr 30May 15May 30Jun 1419601970198019902000201020201951: May 21952: Apr 91953: May 131954: May 21955: May 41956: Apr 161957: Apr 241958: Apr 151959: Mar 301960: May 201961: Apr 291962: Apr 11963: Apr 281964: May 91965: May 91966: Apr 71967: May 31968: Apr 271969: Apr 281970: May 11972: Apr 281973: Apr 221974: May 211975: May 91976: May 21977: May 191978: May 91979: May 131980: May 261981: Apr 101982: May 131983: May 161984: Apr 301985: May 141986: May 101987: Apr 151988: May 91989: Apr 291991: May 41992: Apr 221993: Apr 211994: Apr 301995: May 81996: Apr 301997: Apr 251998: May 151999: May 22000: Apr 202001: Apr 232002: Apr 222003: May 112004: Mar 72005: Apr 132006: Apr 82007: Apr 222008: Apr 222010: May 42011: May 22012: Apr 172013: Apr 202014: May 92015: Apr 182016: Apr 72017: Apr 302018: Apr 152019: May 212020: Apr 162021: Apr 172022: May 132023: Apr 62024: Apr 102025: Apr 21

First fall frost (32°F)

Sep 27Oct 12Oct 27Nov 11Nov 2619601970198019902000201020201951: Oct 231952: Oct 161953: Oct 71954: Oct 261955: Oct 301956: Oct 211957: Oct 231958: Oct 311959: Nov 61960: Oct 311961: Oct 41962: Nov 21963: Nov 61964: Oct 211965: Oct 181966: Oct 171967: Oct 171968: Oct 171969: Oct 131970: Oct 91971: Oct 201972: Nov 11973: Oct 111974: Oct 301975: Oct 141976: Oct 91977: Oct 251978: Oct 271979: Oct 221980: Oct 161981: Oct 171982: Oct 21983: Nov 151984: Oct 191985: Nov 21986: Oct 151987: Nov 71988: Nov 61989: Oct 271990: Oct 141991: Oct 291992: Oct 81993: Oct 281994: Oct 101995: Oct 251996: Oct 221997: Oct 131998: Oct 61999: Oct 182000: Nov 12001: Nov 202002: Oct 42003: Oct 272004: Oct 232005: Nov 12008: Oct 132010: Nov 32012: Oct 262013: Oct 172014: Nov 42015: Nov 62016: Nov 132017: Nov 192018: Nov 12019: Oct 212020: Oct 282021: Oct 132022: Oct 252023: Oct 312024: Oct 202025: Oct 30

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 21Oct 30Apr 20Nov 21
2024Apr 10Oct 20Apr 7Oct 31
2023Apr 6Oct 31Apr 6Oct 31
2022May 13Oct 25Apr 14Oct 25
2021Apr 17Oct 13Mar 28Oct 13
2020Apr 16Oct 28Apr 16Oct 28
2019May 21Oct 21Apr 13Oct 26
2018Apr 15Nov 1Apr 15Nov 12
2017Apr 30Nov 19Apr 30Nov 20
2016Apr 7Nov 13Apr 7Nov 14
2015Apr 18Nov 6Apr 17Nov 6
2014May 9Nov 4Mar 17Nov 17
2013Apr 20Oct 17Apr 20Oct 20
2012Apr 17Oct 26Apr 16Nov 11
2011May 2no dataApr 11no data
2010May 4Nov 3May 1Nov 8
2008Apr 22Oct 13Apr 18Oct 13
2007Apr 22no dataMar 29no data
2006Apr 8no dataMar 25no data
2005Apr 13Nov 1Apr 10Nov 1
2004Mar 7Oct 23Mar 6Nov 2
2003May 11Oct 27Apr 16Oct 27
2002Apr 22Oct 4Apr 21Nov 5
2001Apr 23Nov 20Apr 13Nov 21
2000Apr 20Nov 1Apr 1Nov 8
1999May 2Oct 18Apr 17Oct 18
1998May 15Oct 6Apr 19Nov 4
1997Apr 25Oct 13Apr 25Oct 13
1996Apr 30Oct 22Apr 15Oct 22
1995May 8Oct 25May 8Nov 19
1994Apr 30Oct 10Apr 28Nov 5
1993Apr 21Oct 28Apr 15Oct 31
1992Apr 22Oct 8Mar 25Oct 9
1991May 4Oct 29May 3Oct 29
1990no dataOct 14no dataNov 4
1989Apr 29Oct 27Apr 28Oct 27
1988May 9Nov 6May 7Nov 13
1987Apr 15Nov 7Apr 15Nov 10
1986May 10Oct 15May 9Oct 28
1985May 14Nov 2Apr 2Nov 7
1984Apr 30Oct 19Apr 30Nov 2
1983May 16Nov 15Apr 16Nov 16
1982May 13Oct 2Apr 8Oct 10
1981Apr 10Oct 17Apr 5Oct 17
1980May 26Oct 16May 25Oct 16
1979May 13Oct 22May 12Oct 22
1978May 9Oct 27Apr 21Nov 16
1977May 19Oct 25Apr 22Nov 2
1976May 2Oct 9Apr 18Oct 9
1975May 9Oct 14May 8Oct 14
1974May 21Oct 30May 9Nov 4
1973Apr 22Oct 11Apr 10Oct 11
1972Apr 28Nov 1Apr 21Nov 1
1971no dataOct 20no dataOct 30
1970May 1Oct 9May 1Oct 27
1969Apr 28Oct 13Mar 27Oct 31
1968Apr 27Oct 17Apr 27Oct 18
1967May 3Oct 17May 2Oct 31
1966Apr 7Oct 17Apr 6Oct 31
1965May 9Oct 18Apr 6Nov 12
1964May 9Oct 21Apr 26Nov 6
1963Apr 28Nov 6Apr 19Nov 19
1962Apr 1Nov 2Apr 1Nov 9
1961Apr 29Oct 4Apr 26Nov 15
1960May 20Oct 31Apr 25Nov 16
1959Mar 30Nov 6Mar 28Nov 7
1958Apr 15Oct 31Apr 6Nov 15
1957Apr 24Oct 23Apr 8Nov 7
1956Apr 16Oct 21Apr 5Oct 25
1955May 4Oct 30Apr 14Nov 8
1954May 2Oct 26Apr 2Nov 4
1953May 13Oct 7Apr 28Oct 26
1952Apr 9Oct 16Mar 28Nov 5
1951May 2Oct 23Apr 12Oct 23

"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.