When to plant in Half Moon Bay, CA

Planting dates worked out from Half Moon Bay's own frost records, not a generic zone chart.

Frost is rare in Half Moon Bay: in 13 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.

Safe to plant out

Mar 25

1 year in 10 has a later frost

Average last frost

Feb 4

about a 50% chance of a later one

Average first fall frost

Dec 16

1 year in 10 by Nov 24

Frost-free days

306

median, 1991–2020

Station used: Half Moon Bay · 1.6 km away · station 8 m, town 22 m. How we match towns to stations

Half Moon Bay's weather over time

How the growing season has shifted here, year by year, from the station's own records.

Each year's last spring frostLong-term trend

See the data as a table

Year	Last spring frost
1943	Jan 19
1944	Mar 26
1945	Jan 20
1946	Feb 11
1947	Jan 18
1949	Feb 14
1951	Jan 31
1955	Jan 8
1957	Jan 3
1962	Jan 23
1963	Jan 13
1966	Mar 3
1969	Jan 31
1972	Mar 26
1975	Jan 30
1976	Apr 1
1979	Feb 3
1980	Jan 29
1983	Jan 20
1984	Jan 13
1989	Feb 7
1990	Feb 14
1991	Mar 16
2004	Feb 17
2006	Mar 13
2007	Apr 16
2008	Apr 30
2009	Apr 4
2011	Feb 27
2012	Mar 8
2013	Feb 27
2017	Mar 2
2018	Feb 28
2019	Feb 23
2020	Feb 5
2021	Jan 21
2022	Mar 12
2023	Mar 27
2025	Feb 10

Each year's frost-free daysLong-term trend

See the data as a table

Year	Frost-free days
1940	345
1942	363
1943	345
1944	279
1945	344
1946	322
1947	346
1948	354
1950	363
1951	312
1952	363
1954	363
1955	315
1956	324
1957	361
1958	319
1959	362
1960	363
1961	363
1962	341
1963	351
1964	363
1965	363
1966	302
1967	363
1968	352
1969	333
1970	363
1971	363
1972	256
1974	363
1975	334
1976	273
1977	363
1978	340
1979	330
1980	335
1981	363
1982	363
1983	344
1984	351
1986	363
1989	326
1990	308
1991	289
1992	363
1995	363
1996	363
1997	363
1998	353
1999	363
2000	363
2004	285
2005	329
2006	279
2007	220
2008	233
2009	245
2010	326
2011	293
2012	285
2013	279
2014	363
2015	359
2016	349
2017	294
2018	254
2019	306
2020	276
2021	323
2022	262
2023	278
2024	363
2025	323

Each year's average temperature, April to SeptemberLong-term trend

See the data as a table

Year	Growing-season temperature
1940	14.7 °C
1941	14.7 °C
1942	13.9 °C
1943	13.7 °C
1944	12.9 °C
1945	13.3 °C
1946	13.3 °C
1947	14.4 °C
1948	13.5 °C
1949	13.2 °C
1950	13.0 °C
1951	12.8 °C
1952	13.4 °C
1953	13.6 °C
1954	13.1 °C
1955	12.1 °C
1956	13.6 °C
1957	14.4 °C
1958	15.2 °C
1959	14.5 °C
1960	13.8 °C
1961	14.6 °C
1962	13.0 °C
1963	13.4 °C
1964	13.1 °C
1965	13.4 °C
1966	13.1 °C
1967	13.3 °C
1968	13.7 °C
1969	12.4 °C
1970	12.7 °C
1971	12.5 °C
1972	13.5 °C
1973	13.6 °C
1974	13.7 °C
1975	12.5 °C
1976	13.8 °C
1977	13.5 °C
1978	14.0 °C
1979	13.8 °C
1980	13.8 °C
1981	13.6 °C
1982	13.9 °C
1983	15.0 °C
1984	13.9 °C
1985	14.1 °C
1986	13.9 °C
1989	13.9 °C
1990	14.0 °C
1991	12.3 °C
1992	14.7 °C
1995	14.0 °C
1996	13.3 °C
1997	15.0 °C
1998	13.8 °C
1999	12.9 °C
2000	14.2 °C
2004	14.4 °C
2005	13.9 °C
2006	14.0 °C
2007	13.8 °C
2008	13.1 °C
2009	13.9 °C
2010	13.5 °C
2011	13.6 °C
2012	13.3 °C
2013	14.5 °C
2014	15.3 °C
2015	15.3 °C
2016	14.3 °C
2017	14.5 °C
2018	13.8 °C
2019	14.8 °C
2020	14.6 °C
2021	13.7 °C
2022	13.6 °C
2023	13.5 °C
2024	13.1 °C
2025	14.2 °C
2026	14.9 °C

What this means for you: Since 1943, Half Moon Bay's last spring frost has come about 5 days later per decade, on average. The frost-free season has shrunk by about 6 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.

Source: daily records from Half Moon Bay (NOAA GHCN-Daily). Years with too many missing days are left out.

Nearby towns

El Granada Highlands-Baywood Park Moss Beach Montara Hillsborough Emerald Lake Hills