When to plant in Seneca, PA

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

Safe to plant out

May 17

1 year in 10 has a later frost

Average last frost

May 5

about a 50% chance of a later one

Average first fall frost

Oct 19

1 year in 10 by Oct 8

Frost-free days

164

median, 1991–2020

Station used: Franklin · 10.8 km away · station 309 m, town 443 m. How we match towns to stations

This season

Plan your garden.

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Planting dates for common crops

Crop	Start indoors	Plant out or sow	Harvest from
Tomato	Mar 22 – Apr 5	May 17 – May 31	Jul 11
Sweet pepper	Mar 8 – Mar 22	May 17 – May 31	Jul 16
Lettuce (leaf)	Mar 3 – Mar 10	Apr 7 – Apr 21	May 17
Peas	—	Apr 4 – May 2	May 29
Bush beans	—	May 10 – May 31	Jun 29
Carrot	—	Apr 14 – May 26	Jun 13
Beet	—	Apr 12 – May 24	Jun 1
Potato	—	Apr 14 – May 5	Jun 23
Kale	Feb 28 – Mar 14	Apr 11 – Apr 25	May 24
Broccoli	Feb 24 – Mar 10	Apr 7 – Apr 28	Jun 6
Cucumber	Apr 19 – Apr 26	May 17 – May 31	Jul 6
Summer squash and zucchini	Apr 19 – Apr 26	May 17 – May 31	Jul 1
Winter squash	Apr 19 – Apr 26	May 17 – May 31	Aug 5
Sweet corn	—	May 10 – May 31	Jul 9
Onion (from sets)	—	Apr 7 – Apr 28	Jul 6
Garlic	—	Oct 5 – Nov 2 (fall)	following summer
Spinach	—	Apr 4 – May 2	May 12
Basil	Apr 5 – Apr 19	May 17 – May 31	Jul 13

Plan all 65 crops for Seneca

Seneca'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
1897	Apr 28
1898	May 9
1899	Apr 17
1900	May 22
1902	May 29
1903	May 6
1904	May 12
1905	May 24
1906	Jun 12
1909	May 12
1910	May 13
1911	May 7
1912	Apr 28
1913	May 12
1914	May 3
1915	May 27
1916	Apr 15
1917	May 26
1918	May 2
1919	Apr 30
1920	May 16
1921	May 17
1922	May 1
1923	May 14
1924	May 5
1925	May 25
1926	May 13
1927	May 1
1928	May 24
1929	Jun 3
1930	Jun 1
1931	May 5
1932	May 30
1933	Apr 28
1934	May 26
1935	May 22
1936	May 15
1937	Apr 17
1938	May 25
1939	May 14
1940	May 12
1941	May 14
1942	May 12
1943	May 6
1944	May 1
1945	Jun 6
1946	May 10
1947	May 12
1948	Apr 22
1949	May 12
1950	May 9
1951	May 15
1952	May 4
1953	Apr 22
1954	Apr 13
1955	May 18
1956	May 25
1957	May 8
1958	May 10
1959	May 9
1960	May 2
1961	May 30
1962	May 10
1963	May 24
1964	Apr 12
1966	May 12
1967	May 23
1969	May 1
1970	May 8
1971	May 3
1972	May 11
1973	May 20
1974	May 10
1975	Apr 28
1976	May 13
1977	May 8
1978	May 4
1979	May 5
1980	May 10
1981	May 20
1982	Apr 30
1983	May 19
1984	May 17
1985	May 9
1986	May 5
1987	May 9
1988	Apr 27
1989	Apr 25
1990	Apr 20
1991	Apr 13
1992	Apr 30
1993	Apr 29
1994	May 14
1995	May 8
1996	May 15
1997	May 12
1998	Apr 29
1999	May 1
2000	Apr 29
2001	Apr 30
2002	May 22
2004	May 7
2005	May 7
2006	May 23
2007	Apr 21
2008	Apr 17
2009	May 19
2010	May 11
2011	May 5
2012	Apr 30
2013	May 14
2014	May 7
2015	Apr 26
2016	May 16
2017	May 9
2018	Apr 30
2019	Apr 29
2020	May 14
2021	May 10
2022	Apr 30
2023	May 18
2024	Apr 26
2025	Apr 18
2026	May 5

Each year's frost-free daysLong-term trend

See the data as a table

Year	Frost-free days
1897	142
1898	170
1899	165
1900	141
1902	133
1903	145
1904	131
1905	136
1906	110
1909	138
1910	147
1911	148
1912	170
1913	124
1914	147
1915	124
1916	156
1917	128
1918	151
1919	160
1920	143
1921	149
1922	147
1923	123
1924	156
1925	137
1926	148
1927	145
1928	136
1929	108
1930	119
1931	157
1932	118
1933	168
1934	128
1935	130
1936	141
1937	153
1938	134
1939	153
1942	139
1943	142
1944	166
1945	119
1946	155
1947	137
1948	164
1949	165
1950	169
1951	137
1952	152
1953	168
1954	176
1955	156
1956	137
1957	141
1958	144
1959	130
1960	172
1961	139
1962	167
1963	123
1966	147
1967	142
1969	166
1970	161
1971	184
1972	150
1973	169
1974	136
1975	157
1976	157
1977	158
1978	165
1979	174
1980	156
1981	149
1982	170
1983	160
1984	166
1985	160
1986	157
1987	157
1988	167
1989	180
1990	182
1991	183
1992	170
1993	164
1994	166
1995	161
1996	149
1997	157
1998	183
1999	158
2000	161
2001	160
2002	145
2004	186
2006	142
2007	190
2008	183
2009	147
2010	162
2011	175
2012	161
2013	164
2014	172
2015	174
2016	162
2017	175
2018	171
2019	172
2020	145
2021	177
2022	170
2023	157
2024	181
2025	191

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

See the data as a table

Year	Growing-season temperature
1897	16.4 °C
1898	17.6 °C
1899	17.6 °C
1900	18.0 °C
1902	16.4 °C
1903	16.6 °C
1904	16.8 °C
1905	17.0 °C
1906	17.3 °C
1909	16.3 °C
1910	16.4 °C
1911	17.7 °C
1912	17.0 °C
1913	17.1 °C
1914	17.0 °C
1915	16.6 °C
1916	16.9 °C
1917	15.5 °C
1918	16.8 °C
1919	17.0 °C
1920	16.3 °C
1921	18.7 °C
1922	18.0 °C
1923	16.5 °C
1924	15.0 °C
1925	17.1 °C
1926	15.7 °C
1927	15.5 °C
1928	15.5 °C
1929	16.4 °C
1930	17.0 °C
1931	18.0 °C
1932	16.6 °C
1933	18.2 °C
1934	18.2 °C
1935	17.1 °C
1936	17.5 °C
1937	16.6 °C
1938	16.3 °C
1939	16.3 °C
1940	15.8 °C
1941	17.1 °C
1942	16.9 °C
1943	16.3 °C
1944	17.2 °C
1945	16.5 °C
1946	15.9 °C
1947	16.9 °C
1948	16.9 °C
1949	16.9 °C
1950	15.2 °C
1952	16.3 °C
1953	17.4 °C
1954	17.3 °C
1955	18.4 °C
1956	16.1 °C
1957	16.9 °C
1958	16.6 °C
1959	18.4 °C
1960	17.5 °C
1961	16.8 °C
1963	16.3 °C
1964	17.0 °C
1967	15.8 °C
1968	16.7 °C
1969	16.4 °C
1970	17.1 °C
1971	16.1 °C
1972	16.2 °C
1973	17.4 °C
1974	15.9 °C
1975	16.5 °C
1976	15.8 °C
1978	15.6 °C
1979	15.2 °C
1980	16.4 °C
1981	16.8 °C
1982	16.4 °C
1983	17.1 °C
1984	16.3 °C
1985	17.0 °C
1986	17.1 °C
1987	17.5 °C
1988	17.0 °C
1989	16.2 °C
1990	16.4 °C
1991	18.2 °C
1992	15.9 °C
1993	16.9 °C
1994	16.5 °C
1995	16.9 °C
1996	16.5 °C
1997	15.3 °C
1998	17.8 °C
1999	17.8 °C
2000	16.3 °C
2001	16.8 °C
2002	17.4 °C
2004	17.1 °C
2005	18.0 °C
2006	17.3 °C
2007	17.2 °C
2008	17.0 °C
2009	16.5 °C
2010	18.2 °C
2011	18.1 °C
2012	17.7 °C
2013	17.1 °C
2014	16.8 °C
2015	17.9 °C
2016	17.9 °C
2017	17.6 °C
2018	18.1 °C
2019	17.9 °C
2020	17.1 °C
2021	17.7 °C
2022	17.4 °C
2023	17.2 °C
2024	18.4 °C
2025	18.2 °C
2026	18.6 °C

What this means for you: Since 1897, Seneca's last spring frost has come about 1 day earlier per decade, on average. The frost-free season has grown by about 3 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.

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

Nearby towns

Woodland Heights Oil City Hasson Heights Franklin Sugarcreek Knox