Frost history / Riverside Citrus Exp, CA
Riverside Citrus Exp, CA: frost dates by year
Last spring and first fall frost at NOAA station USC00047473, 1956 to 2009, measured from daily minimum temperatures.
Elevation 986 ft, 33.967, -117.361. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Feb 4 | Dec 13 |
| Earliest | Jan 3 (1974) | Oct 28 (1970) |
| Latest | Mar 15 (1962) | Dec 30 (1964) |
| Trend | 3.6 days earlier per decade | 2.2 days later per decade |
| Years with data | 51, 18 with no freeze | 53, 21 with no freeze |
At 28°F (hard freeze) the median last spring date is Jan 22 and the median first fall date is Dec 14.
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 |
|---|---|---|---|---|
| 2009 | none | no data | none | no data |
| 2008 | none | Dec 26 | none | none |
| 2007 | Jan 18 | none | Jan 14 | none |
| 2006 | no data | Dec 20 | no data | none |
| 2005 | none | none | none | none |
| 2004 | Feb 13 | Nov 30 | none | none |
| 2003 | none | Dec 27 | none | none |
| 2002 | Feb 1 | Dec 24 | none | none |
| 2001 | no data | none | no data | none |
| 2000 | no data | Nov 14 | no data | none |
| 1999 | none | none | none | none |
| 1998 | none | Dec 22 | none | none |
| 1997 | none | Dec 27 | none | none |
| 1996 | Feb 27 | none | none | none |
| 1995 | none | none | none | none |
| 1994 | none | Nov 20 | none | none |
| 1993 | Jan 4 | none | none | none |
| 1992 | none | Dec 20 | none | none |
| 1991 | Jan 30 | Dec 2 | none | none |
| 1990 | Mar 13 | Dec 18 | none | Dec 22 |
| 1989 | Feb 7 | Dec 12 | none | none |
| 1988 | Jan 21 | Dec 26 | none | none |
| 1987 | Feb 27 | Dec 15 | none | Dec 15 |
| 1986 | Feb 10 | none | none | none |
| 1985 | none | Dec 10 | none | none |
| 1984 | none | none | none | none |
| 1983 | Jan 21 | none | none | none |
| 1982 | Jan 8 | Dec 1 | none | none |
| 1981 | none | none | none | none |
| 1980 | none | none | none | none |
| 1979 | Feb 4 | none | none | none |
| 1978 | none | Dec 6 | none | Dec 6 |
| 1977 | none | none | none | none |
| 1976 | Jan 3 | none | none | none |
| 1975 | none | none | none | none |
| 1974 | Jan 3 | Dec 24 | none | none |
| 1973 | Jan 8 | none | none | none |
| 1972 | Jan 29 | Dec 9 | none | Dec 12 |
| 1971 | Feb 28 | Oct 30 | none | none |
| 1970 | Jan 30 | Oct 28 | Jan 5 | none |
| 1969 | Mar 8 | Dec 27 | Jan 30 | Dec 30 |
| 1968 | none | Dec 18 | none | Dec 21 |
| 1967 | Mar 7 | Dec 14 | none | none |
| 1966 | Mar 5 | none | none | none |
| 1965 | Mar 3 | Nov 26 | Feb 12 | none |
| 1964 | Mar 9 | Dec 30 | none | none |
| 1963 | Jan 20 | none | Jan 14 | none |
| 1962 | Mar 15 | Dec 26 | Feb 28 | none |
| 1961 | Jan 9 | Dec 8 | none | none |
| 1960 | Jan 18 | Dec 6 | Jan 3 | Dec 9 |
| 1959 | Feb 9 | none | none | none |
| 1958 | Mar 3 | Nov 16 | none | Nov 17 |
| 1957 | Feb 4 | none | none | none |
| 1956 | Mar 13 | Dec 9 | Feb 17 | none |
"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.