Last Frost Day

Frost history / Alpine, AZ

Alpine, AZ: frost dates by year

Last spring and first fall frost at NOAA station USC00020159, 1951 to 2025, measured from daily minimum temperatures.

Elevation 8,050 ft, 33.849, -109.147. Download the data (JSON) · NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 20Sep 17
EarliestMay 30 (2007)Aug 18 (1960)
LatestJul 7 (1987)Oct 23 (2015)
Trend1.3 days earlier per decade3.3 days later per decade
Years with data4946

At 28°F (hard freeze) the median last spring date is Jun 13 and the median first fall date is Sep 27.

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)

May 15May 30Jun 14Jun 29Jul 1419601970198019902000201020201951: Jun 291952: Jun 281956: Jun 171957: Jun 231958: Jun 141960: Jun 271961: Jun 101962: Jun 181963: Jun 81964: Jun 231965: Jun 281966: Jun 111970: Jun 201971: Jun 121972: Jun 271974: Jun 111975: Jun 291976: Jun 301984: Jun 171985: Jul 21986: Jun 201987: Jul 71988: Jun 131989: Jun 261990: Jun 201991: Jun 281992: Jul 31995: Jul 31996: Jun 11997: Jul 11998: Jun 201999: Jun 142000: Jun 102001: Jun 142002: Jun 112003: Jun 262004: Jul 32005: Jun 192006: Jun 12007: May 302010: Jun 232011: Jun 222012: Jun 182013: Jun 262016: Jun 172017: Jun 152022: Jun 32024: Jun 42025: May 30

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201952: Sep 71955: Sep 11956: Aug 291957: Sep 121959: Sep 81960: Aug 181961: Sep 41962: Sep 61963: Sep 291965: Sep 211970: Sep 151971: Sep 201973: Sep 31975: Sep 221985: Sep 51987: Sep 161988: Sep 51989: Aug 251990: Sep 291991: Sep 141992: Sep 51993: Sep 91994: Sep 151995: Sep 231996: Sep 191997: Oct 81998: Sep 241999: Sep 282000: Sep 252001: Sep 92002: Aug 242003: Sep 182004: Sep 222005: Sep 142006: Sep 172007: Sep 252009: Sep 172010: Oct 32014: Sep 302015: Oct 232016: Sep 162017: Sep 232018: Oct 52021: Oct 12022: Sep 292023: 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 30no dataMay 30no data
2024Jun 4no dataMay 30no data
2023no dataSep 20no dataOct 3
2022Jun 3Sep 29May 25Oct 19
2021no dataOct 1no dataOct 10
2018no dataOct 5no dataOct 5
2017Jun 15Sep 23Jun 14Sep 23
2016Jun 17Sep 16Jun 1Sep 22
2015no dataOct 23no dataNov 3
2014no dataSep 30no dataSep 30
2013Jun 26no dataJun 10no data
2012Jun 18no dataJun 18no data
2011Jun 22no dataJun 20no data
2010Jun 23Oct 3Jun 13Oct 10
2009no dataSep 17no dataSep 21
2007May 30Sep 25May 24Oct 7
2006Jun 1Sep 17May 7Sep 18
2005Jun 19Sep 14May 14Sep 15
2004Jul 3Sep 22Jun 11Sep 22
2003Jun 26Sep 18Jun 10Oct 16
2002Jun 11Aug 24May 25Oct 4
2001Jun 14Sep 9Jun 14Oct 11
2000Jun 10Sep 25May 26Sep 25
1999Jun 14Sep 28Jun 7Sep 28
1998Jun 20Sep 24Jun 14Oct 6
1997Jul 1Oct 8Jul 1Oct 8
1996Jun 1Sep 19May 31Sep 28
1995Jul 3Sep 23Jul 3Sep 30
1994no dataSep 15no dataOct 2
1993no dataSep 9no dataSep 19
1992Jul 3Sep 5Jun 17Sep 30
1991Jun 28Sep 14Jun 23Oct 6
1990Jun 20Sep 29Jun 16Oct 9
1989Jun 26Aug 25Jun 26Sep 14
1988Jun 13Sep 5Jun 13Sep 23
1987Jul 7Sep 16Jun 22Sep 30
1986Jun 20no dataMay 20no data
1985Jul 2Sep 5Jun 27Sep 13
1984Jun 17no dataJun 9no data
1976Jun 30no dataJun 30no data
1975Jun 29Sep 22Jun 26Sep 22
1974Jun 11no dataJun 11no data
1973no dataSep 3no dataSep 26
1972Jun 27no dataJun 27no data
1971Jun 12Sep 20Jun 6Sep 20
1970Jun 20Sep 15Jun 17Sep 15
1966Jun 11no dataMay 28no data
1965Jun 28Sep 21Jun 28Sep 21
1964Jun 23no dataJun 18no data
1963Jun 8Sep 29May 5Oct 3
1962Jun 18Sep 6Jun 17Sep 28
1961Jun 10Sep 4Jun 5Sep 4
1960Jun 27Aug 18May 30Sep 23
1959no dataSep 8no dataSep 14
1958Jun 14no dataJun 11no data
1957Jun 23Sep 12Jun 21Sep 19
1956Jun 17Aug 29Jun 7Sep 11
1955no dataSep 1no dataSep 21
1952Jun 28Sep 7Jun 28Sep 8
1951Jun 29no dataJun 27no data

"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 1991–2020 frost probabilities.