When to plant in Byron, CA

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

Frost is rare in Byron: in 5 of the last 27 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

Feb 24

1 year in 10 has a later frost

Average last frost

Jan 26

about a 50% chance of a later one

Average first fall frost

Dec 13

1 year in 10 by Nov 30

Frost-free days

323

median, 1991–2020

Station used: Tracy Pumping Plt · 9.3 km away · station 19 m, town 10 m. How we match towns to stations

Byron'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
1956	Mar 13
1957	Feb 5
1958	Mar 12
1959	Jan 4
1960	Feb 24
1963	Jan 25
1964	Mar 7
1965	Feb 24
1966	Mar 4
1967	Apr 1
1968	Jan 28
1969	Feb 8
1970	Jan 6
1971	Mar 6
1972	Feb 3
1973	Jan 27
1974	Mar 9
1975	Feb 24
1976	Mar 4
1977	Jan 11
1979	Feb 5
1980	Feb 9
1982	Feb 10
1983	Jan 11
1984	Feb 23
1985	Mar 8
1986	Feb 10
1994	Feb 23
1995	Apr 18
1997	Jan 14
1999	Jan 30
2000	Jan 6
2001	Feb 1
2002	Feb 5
2003	Feb 9
2004	Jan 23
2006	Feb 19
2007	Jan 31
2008	Jan 19
2009	Jan 11
2010	Jan 6
2011	Feb 26
2012	Jan 18
2013	Feb 10
2015	Jan 3
2017	Jan 6
2018	Feb 28
2019	Feb 11
2020	Jan 17
2022	Feb 25
2023	Feb 18
2025	Jan 28
2026	Feb 21

Each year's frost-free daysLong-term trend

See the data as a table

Year	Frost-free days
1956	252
1957	290
1958	249
1959	314
1960	284
1963	315
1964	253
1965	289
1966	265
1967	239
1968	303
1969	282
1970	339
1971	237
1972	292
1973	337
1974	264
1975	270
1976	268
1977	338
1978	317
1979	288
1980	291
1981	363
1982	302
1983	353
1984	296
1986	290
1994	278
1995	256
1996	351
1997	330
1998	342
1999	318
2000	315
2001	332
2002	328
2003	309
2004	310
2005	347
2006	283
2007	315
2008	323
2009	325
2010	323
2011	282
2012	335
2013	297
2014	363
2015	330
2016	350
2017	337
2018	305
2019	322
2020	336
2021	343
2022	277
2023	281
2024	363
2025	336

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

See the data as a table

Year	Growing-season temperature
1956	20.9 °C
1957	21.7 °C
1958	21.7 °C
1959	22.2 °C
1960	22.0 °C
1963	20.4 °C
1964	20.9 °C
1965	20.2 °C
1966	21.8 °C
1967	21.1 °C
1968	20.6 °C
1969	21.6 °C
1970	21.4 °C
1971	20.8 °C
1972	21.5 °C
1973	21.9 °C
1974	21.5 °C
1975	20.5 °C
1976	21.2 °C
1977	21.2 °C
1978	21.3 °C
1979	22.1 °C
1980	20.6 °C
1981	22.5 °C
1982	20.5 °C
1983	21.1 °C
1984	22.6 °C
1985	22.0 °C
1986	20.9 °C
1994	21.5 °C
1995	20.8 °C
1996	22.5 °C
2001	22.7 °C
2002	21.9 °C
2003	21.9 °C
2004	22.4 °C
2005	22.0 °C
2006	22.3 °C
2009	22.7 °C
2010	21.1 °C
2011	21.2 °C
2012	22.2 °C
2013	23.0 °C
2014	23.4 °C
2015	22.9 °C
2016	22.8 °C
2017	23.3 °C
2018	22.6 °C
2019	23.0 °C
2020	24.1 °C
2021	24.3 °C
2022	23.9 °C
2023	22.3 °C
2024	23.9 °C
2025	23.1 °C
2026	23.0 °C

What this means for you: Since 1956, Byron's last spring frost has come about 3 days earlier per decade, on average. The frost-free season has grown by about 8 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.

Source: daily records from Tracy Pumping Plt (NOAA GHCN-Daily). Years with too many missing days are left out.

Nearby towns

Discovery Bay Brentwood Knightsen Mountain House Oakley Bethel Island