Frost history / Pomona/Fairplex, CA
Pomona/Fairplex, CA: frost dates by year
Last spring and first fall frost at NOAA station USC00047050, 1951 to 2012, measured from daily minimum temperatures.
Elevation 999 ft, 34.082, -117.766. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Feb 22 | Dec 11 |
| Earliest | Jan 2 (1974) | Nov 1 (1956) |
| Latest | Apr 12 (1953) | Dec 31 (2010) |
| Trend | 7.1 days earlier per decade | 4.9 days later per decade |
| Years with data | 51, 10 with no freeze | 49, 12 with no freeze |
At 28°F (hard freeze) the median last spring date is Feb 13 and the median first fall date is Dec 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)
First fall frost (32°F)
Dots are single years. The gray line is the median, the green line the fitted trend.
Year by year
| Year | Last spring 32°F | First fall 32°F | Last spring 28°F | First fall 28°F |
|---|---|---|---|---|
| 2012 | none | no data | none | no data |
| 2011 | Feb 27 | none | none | none |
| 2010 | no data | Dec 31 | no data | none |
| 2009 | Jan 5 | no data | none | no data |
| 2008 | none | no data | none | no data |
| 2007 | Jan 17 | no data | Jan 14 | no data |
| 2006 | Mar 12 | no data | none | no data |
| 2005 | none | Dec 5 | none | none |
| 2004 | no data | Nov 30 | no data | none |
| 2003 | no data | Dec 28 | no data | none |
| 2002 | Jan 31 | no data | none | no data |
| 2001 | no data | none | no data | none |
| 1993 | Jan 4 | Dec 22 | none | none |
| 1992 | Jan 29 | Dec 14 | none | none |
| 1991 | none | Dec 1 | none | none |
| 1990 | Feb 20 | Dec 17 | Feb 15 | Dec 21 |
| 1989 | Feb 6 | none | Feb 6 | none |
| 1988 | Mar 11 | Dec 25 | none | Dec 29 |
| 1987 | Mar 22 | Dec 14 | Jan 17 | Dec 25 |
| 1986 | none | none | none | none |
| 1985 | Mar 3 | Dec 11 | Feb 5 | none |
| 1984 | none | Dec 14 | none | none |
| 1983 | Jan 2 | Nov 28 | none | none |
| 1982 | Jan 22 | Dec 26 | none | none |
| 1981 | none | none | none | none |
| 1980 | none | none | none | none |
| 1979 | Feb 4 | Dec 12 | none | none |
| 1978 | none | Dec 7 | none | Dec 7 |
| 1977 | none | none | none | none |
| 1976 | Mar 4 | none | Jan 2 | none |
| 1975 | Feb 17 | none | none | none |
| 1974 | Jan 2 | Dec 24 | none | Dec 24 |
| 1973 | Jan 27 | none | none | none |
| 1972 | Jan 9 | Dec 9 | none | none |
| 1971 | Mar 2 | Dec 8 | Mar 2 | none |
| 1970 | Jan 5 | none | none | none |
| 1969 | Feb 1 | Dec 27 | Jan 30 | Dec 30 |
| 1968 | Jan 30 | Dec 12 | none | Dec 21 |
| 1967 | Feb 22 | Dec 14 | none | Dec 14 |
| 1966 | Mar 4 | Dec 27 | Mar 3 | none |
| 1965 | Feb 17 | Dec 15 | Feb 12 | Dec 23 |
| 1964 | Mar 9 | Nov 14 | none | Nov 15 |
| 1963 | Apr 2 | Dec 11 | Jan 20 | none |
| 1962 | Mar 15 | Nov 19 | Feb 28 | Dec 26 |
| 1961 | Jan 8 | Dec 13 | none | none |
| 1960 | Feb 25 | Nov 28 | Jan 18 | Dec 9 |
| 1959 | Feb 23 | none | none | none |
| 1958 | Mar 3 | Nov 16 | none | Nov 17 |
| 1957 | Feb 5 | Nov 17 | Jan 31 | none |
| 1956 | Apr 2 | Nov 1 | Mar 12 | Dec 9 |
| 1955 | Apr 5 | Nov 23 | Feb 22 | Dec 30 |
| 1954 | Mar 26 | Nov 30 | Mar 14 | Dec 28 |
| 1953 | Apr 12 | Nov 19 | Mar 3 | Dec 24 |
| 1952 | Mar 23 | Nov 24 | Mar 9 | none |
| 1951 | Mar 14 | Nov 24 | Feb 28 | Dec 6 |
"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.