Frost history / Skyline Ridge Preserve, CA
Skyline Ridge Preserve, CA: frost dates by year
Last spring and first fall frost at NOAA station USC00048273, 1997 to 2025, measured from daily minimum temperatures.
Elevation 2,270 ft, 37.313, -122.185. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Mar 30 | Dec 6 |
| Earliest | Jan 1 (2016) | Nov 11 (2022) |
| Latest | Apr 14 (1998) | Dec 27 (2014) |
| Trend | 9.4 days earlier per decade | 3.5 days earlier per decade |
| Years with data | 19, 1 with no freeze | 15, 4 with no freeze |
At 28°F (hard freeze) the median last spring date is Jan 24 and the median first fall date is Dec 8.
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 |
|---|---|---|---|---|
| 2025 | Feb 10 | none | none | none |
| 2024 | Apr 5 | none | none | none |
| 2023 | Apr 4 | none | Apr 4 | none |
| 2022 | Apr 12 | Nov 11 | none | none |
| 2021 | Mar 17 | Dec 14 | none | none |
| 2020 | Mar 26 | none | none | none |
| 2019 | Feb 23 | no data | none | no data |
| 2018 | Mar 5 | Dec 1 | Feb 23 | none |
| 2017 | Apr 9 | Dec 6 | Jan 6 | none |
| 2016 | Jan 1 | Dec 16 | Jan 1 | none |
| 2015 | none | Nov 26 | none | none |
| 2014 | Feb 4 | Dec 27 | none | none |
| 2013 | Mar 7 | Dec 4 | Jan 14 | Dec 4 |
| 2012 | Apr 6 | Dec 13 | Jan 17 | Dec 19 |
| 2010 | Apr 3 | no data | none | no data |
| 2009 | no data | Dec 6 | no data | Dec 8 |
| 2006 | Mar 13 | no data | Feb 18 | no data |
| 2004 | no data | Nov 29 | no data | none |
| 1999 | Apr 10 | no data | Jan 24 | no data |
| 1998 | Apr 14 | no data | none | no data |
| 1997 | Apr 9 | no data | Apr 2 | no 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 to 2020 frost probabilities.