When to plant in Palo Alto, CA
Planting dates worked out from Palo Alto's own frost records, not a generic zone chart.
Frost is rare in Palo Alto: in 8 of the last 26 springs there was none at all. Frost dates matter less here than heat, so the planting table below is left out.
Station used: Redwood City · 9.3 km away · station 9 m, town 9 m. How we match towns to stations
Palo Alto's weather over time
How the growing season has shifted here, year by year, from the station's own records.
See the data as a table
| Year | Last spring frost |
|---|---|
| 1931 | Apr 3 |
| 1932 | Mar 4 |
| 1933 | Apr 18 |
| 1934 | Jan 12 |
| 1935 | Mar 11 |
| 1936 | Feb 8 |
| 1937 | Feb 27 |
| 1938 | Feb 17 |
| 1939 | Mar 1 |
| 1940 | Jan 21 |
| 1942 | Jan 4 |
| 1943 | Feb 10 |
| 1945 | Jan 24 |
| 1946 | Feb 14 |
| 1947 | Feb 1 |
| 1948 | Mar 4 |
| 1949 | Feb 14 |
| 1950 | Mar 13 |
| 1951 | Mar 11 |
| 1952 | Jan 9 |
| 1953 | Mar 3 |
| 1954 | Jan 25 |
| 1955 | Feb 28 |
| 1956 | Feb 17 |
| 1957 | Feb 5 |
| 1958 | Jan 7 |
| 1959 | Feb 13 |
| 1960 | Jan 17 |
| 1961 | Jan 21 |
| 1962 | Feb 28 |
| 1963 | Jan 22 |
| 1964 | Mar 25 |
| 1965 | Feb 12 |
| 1966 | Mar 17 |
| 1967 | Mar 5 |
| 1968 | Jan 28 |
| 1969 | Feb 3 |
| 1970 | Jan 6 |
| 1971 | Mar 6 |
| 1972 | Feb 2 |
| 1973 | Feb 1 |
| 1974 | Feb 7 |
| 1975 | Feb 23 |
| 1976 | Mar 9 |
| 1977 | Mar 14 |
| 1979 | Feb 4 |
| 1980 | Jan 30 |
| 1981 | Feb 3 |
| 1982 | Jan 11 |
| 1983 | Jan 20 |
| 1984 | Jan 18 |
| 1985 | Feb 10 |
| 1987 | Jan 21 |
| 1988 | Feb 6 |
| 1989 | Feb 14 |
| 1990 | Feb 20 |
| 1991 | Jan 30 |
| 1992 | Jan 25 |
| 1993 | Jan 5 |
| 1994 | Feb 13 |
| 1996 | Feb 26 |
| 1997 | Jan 14 |
| 2001 | Feb 9 |
| 2003 | Feb 10 |
| 2004 | Jan 21 |
| 2007 | Feb 2 |
| 2009 | Jan 27 |
| 2011 | Feb 27 |
| 2012 | Jan 18 |
| 2013 | Feb 20 |
| 2015 | Jan 3 |
| 2017 | Jan 6 |
| 2018 | Feb 24 |
| 2019 | Feb 19 |
| 2022 | Feb 25 |
| 2023 | Feb 18 |
| 2025 | Feb 10 |
See the data as a table
| Year | Frost-free days |
|---|---|
| 1931 | 223 |
| 1932 | 277 |
| 1933 | 225 |
| 1934 | 324 |
| 1935 | 237 |
| 1936 | 273 |
| 1937 | 302 |
| 1938 | 267 |
| 1939 | 298 |
| 1940 | 305 |
| 1941 | 363 |
| 1942 | 360 |
| 1943 | 323 |
| 1944 | 363 |
| 1945 | 322 |
| 1946 | 262 |
| 1947 | 291 |
| 1948 | 268 |
| 1949 | 299 |
| 1950 | 292 |
| 1951 | 271 |
| 1952 | 318 |
| 1953 | 297 |
| 1954 | 308 |
| 1955 | 277 |
| 1956 | 277 |
| 1957 | 328 |
| 1958 | 313 |
| 1959 | 296 |
| 1960 | 323 |
| 1961 | 299 |
| 1962 | 299 |
| 1963 | 322 |
| 1964 | 236 |
| 1965 | 305 |
| 1966 | 252 |
| 1967 | 271 |
| 1968 | 308 |
| 1969 | 298 |
| 1970 | 347 |
| 1971 | 283 |
| 1972 | 305 |
| 1973 | 332 |
| 1974 | 318 |
| 1975 | 268 |
| 1976 | 263 |
| 1977 | 291 |
| 1978 | 316 |
| 1979 | 289 |
| 1980 | 334 |
| 1981 | 330 |
| 1982 | 332 |
| 1983 | 344 |
| 1984 | 332 |
| 1985 | 275 |
| 1986 | 363 |
| 1987 | 337 |
| 1988 | 322 |
| 1989 | 300 |
| 1990 | 286 |
| 1991 | 318 |
| 1992 | 326 |
| 1993 | 322 |
| 1994 | 278 |
| 1995 | 363 |
| 1996 | 292 |
| 1997 | 342 |
| 1998 | 339 |
| 1999 | 348 |
| 2003 | 323 |
| 2004 | 312 |
| 2007 | 313 |
| 2009 | 312 |
| 2010 | 326 |
| 2011 | 281 |
| 2012 | 334 |
| 2013 | 286 |
| 2014 | 363 |
| 2015 | 327 |
| 2016 | 350 |
| 2017 | 349 |
| 2018 | 309 |
| 2019 | 314 |
| 2020 | 362 |
| 2021 | 363 |
| 2022 | 279 |
| 2023 | 315 |
| 2024 | 363 |
| 2025 | 323 |
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1931 | 17.9 °C |
| 1932 | 16.6 °C |
| 1933 | 16.0 °C |
| 1934 | 17.8 °C |
| 1935 | 17.4 °C |
| 1936 | 18.3 °C |
| 1937 | 17.5 °C |
| 1938 | 18.1 °C |
| 1939 | 18.4 °C |
| 1940 | 18.2 °C |
| 1941 | 17.8 °C |
| 1942 | 18.0 °C |
| 1944 | 18.3 °C |
| 1945 | 18.3 °C |
| 1946 | 17.6 °C |
| 1947 | 18.3 °C |
| 1948 | 17.1 °C |
| 1949 | 17.9 °C |
| 1950 | 18.2 °C |
| 1951 | 17.5 °C |
| 1952 | 18.0 °C |
| 1953 | 17.3 °C |
| 1954 | 18.0 °C |
| 1955 | 16.7 °C |
| 1956 | 17.4 °C |
| 1957 | 18.5 °C |
| 1958 | 18.9 °C |
| 1959 | 19.1 °C |
| 1960 | 18.4 °C |
| 1961 | 18.9 °C |
| 1962 | 18.0 °C |
| 1963 | 18.2 °C |
| 1964 | 17.7 °C |
| 1965 | 17.8 °C |
| 1966 | 18.8 °C |
| 1967 | 17.9 °C |
| 1968 | 18.2 °C |
| 1969 | 18.3 °C |
| 1970 | 18.3 °C |
| 1971 | 17.9 °C |
| 1972 | 18.5 °C |
| 1973 | 18.8 °C |
| 1974 | 18.3 °C |
| 1975 | 17.5 °C |
| 1976 | 18.4 °C |
| 1977 | 18.1 °C |
| 1978 | 18.7 °C |
| 1979 | 18.8 °C |
| 1980 | 18.1 °C |
| 1981 | 19.2 °C |
| 1983 | 18.9 °C |
| 1984 | 19.2 °C |
| 1985 | 18.4 °C |
| 1986 | 17.9 °C |
| 1987 | 18.4 °C |
| 1988 | 18.5 °C |
| 1989 | 18.4 °C |
| 1990 | 18.8 °C |
| 1991 | 17.6 °C |
| 1992 | 19.3 °C |
| 1993 | 19.1 °C |
| 1994 | 18.1 °C |
| 1995 | 18.2 °C |
| 1996 | 18.6 °C |
| 1997 | 19.3 °C |
| 1998 | 17.7 °C |
| 1999 | 17.4 °C |
| 2002 | 18.0 °C |
| 2003 | 18.8 °C |
| 2004 | 18.8 °C |
| 2007 | 18.6 °C |
| 2009 | 18.5 °C |
| 2010 | 17.1 °C |
| 2011 | 17.5 °C |
| 2012 | 17.9 °C |
| 2013 | 19.0 °C |
| 2014 | 19.3 °C |
| 2015 | 19.1 °C |
| 2016 | 18.6 °C |
| 2017 | 19.2 °C |
| 2018 | 18.1 °C |
| 2019 | 19.0 °C |
| 2020 | 19.5 °C |
| 2021 | 18.3 °C |
| 2022 | 18.9 °C |
| 2023 | 18.1 °C |
| 2024 | 18.8 °C |
| 2025 | 18.6 °C |
| 2026 | 18.7 °C |
What this means for you: Since 1931, Palo Alto's last spring frost has come about 2 days earlier per decade, on average. The frost-free season has grown by about 5 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Redwood City (NOAA GHCN-Daily). Years with too many missing days are left out.