When to plant in Mount Ayr, IA

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

Safe to plant out

May 11

1 year in 10 has a later frost

Average last frost

Apr 27

about a 50% chance of a later one

Average first fall frost

Oct 8

1 year in 10 by Sep 22

Frost-free days

160

median, 1991–2020

Station used: Mt Ayr · 1.2 km away · station 348 m, town 372 m. How we match towns to stations

This season

Plan your garden.

Build my Mount Ayr plan

Planting dates for common crops

Crop	Start indoors	Plant out or sow	Harvest from
Tomato	Mar 16 – Mar 30	May 11 – May 25	Jul 5
Sweet pepper	Mar 2 – Mar 16	May 11 – May 25	Jul 10
Lettuce (leaf)	Feb 23 – Mar 2	Mar 30 – Apr 13	May 9
Peas	—	Mar 26 – Apr 23	May 20
Bush beans	—	May 4 – May 25	Jun 23
Carrot	—	Apr 6 – May 18	Jun 5
Beet	—	Apr 5 – May 17	May 25
Potato	—	Apr 6 – Apr 27	Jun 15
Kale	Feb 19 – Mar 5	Apr 2 – Apr 16	May 15
Broccoli	Feb 16 – Mar 2	Mar 30 – Apr 20	May 29
Cucumber	Apr 13 – Apr 20	May 11 – May 25	Jun 30
Summer squash and zucchini	Apr 13 – Apr 20	May 11 – May 25	Jun 25
Winter squash	Apr 13 – Apr 20	May 11 – May 25	Jul 30
Sweet corn	—	May 4 – May 25	Jul 3
Onion (from sets)	—	Mar 30 – Apr 20	Jun 28
Garlic	—	Sep 24 – Oct 22 (fall)	following summer
Spinach	—	Mar 26 – Apr 23	May 3
Basil	Mar 30 – Apr 13	May 11 – May 25	Jul 7

Plan all 65 crops for Mount Ayr

Mount Ayr'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
1895	May 12
1896	Apr 4
1897	Apr 19
1898	Apr 13
1899	Apr 16
1900	May 3
1901	Apr 20
1902	Apr 26
1903	May 3
1904	Apr 21
1905	Apr 18
1906	May 9
1907	May 27
1908	May 2
1909	May 2
1910	Apr 25
1911	May 2
1912	Apr 16
1913	Apr 12
1914	Apr 20
1915	May 9
1916	Apr 10
1917	May 4
1918	Apr 21
1919	Apr 26
1920	Apr 28
1921	May 3
1922	Apr 19
1923	May 9
1924	May 24
1925	May 25
1926	Apr 28
1927	Apr 24
1928	Apr 27
1929	May 5
1930	Apr 24
1931	May 7
1932	Apr 27
1933	Apr 23
1934	Apr 27
1935	May 4
1936	Apr 22
1937	Apr 25
1938	Apr 22
1939	Apr 21
1940	May 1
1941	Apr 24
1942	May 4
1943	Apr 20
1944	May 6
1945	Apr 18
1946	May 12
1948	Apr 14
1949	Apr 19
1950	May 1
1951	Apr 23
1952	Apr 16
1953	May 13
1954	May 5
1955	Apr 7
1956	Apr 24
1957	Apr 14
1958	Apr 29
1959	May 15
1960	May 1
1962	Apr 17
1963	May 23
1964	Apr 9
1965	Apr 28
1966	May 10
1970	May 2
1971	Apr 29
1972	Apr 24
1973	Apr 16
1974	Apr 14
1975	Apr 20
1977	Apr 6
1978	Apr 22
1979	Apr 28
1980	May 8
1981	Apr 6
1984	Apr 6
1985	Apr 9
1986	Apr 22
1987	Apr 12
1988	Apr 28
1989	May 7
1990	May 2
1991	Apr 24
1992	May 6
1993	Apr 18
1994	May 8
1995	Apr 27
1996	Apr 30
1997	May 13
1998	Apr 18
1999	Apr 19
2000	Apr 12
2001	Apr 25
2002	Apr 26
2004	Apr 14
2005	May 1
2008	Apr 29
2009	Apr 15
2010	May 9
2011	May 4
2012	Apr 21
2013	May 12
2014	May 17
2015	Apr 23
2016	Apr 12
2017	Apr 23
2018	Apr 26
2019	Apr 20
2020	May 11
2021	May 5
2022	Apr 27

Each year's frost-free daysLong-term trend

See the data as a table

Year	Frost-free days
1895	140
1896	194
1897	192
1898	186
1899	165
1900	187
1901	150
1902	139
1903	167
1904	184
1905	175
1906	152
1907	137
1908	148
1909	162
1910	179
1911	171
1912	162
1913	162
1914	189
1915	148
1916	171
1917	156
1918	151
1919	167
1920	154
1921	157
1922	175
1923	162
1924	150
1925	136
1926	149
1927	149
1928	150
1929	170
1930	175
1931	177
1932	165
1933	177
1934	183
1935	152
1936	182
1937	171
1938	149
1939	161
1940	188
1941	185
1942	142
1943	177
1944	156
1945	173
1946	152
1948	185
1949	162
1950	154
1951	157
1952	172
1953	131
1954	175
1955	183
1956	184
1957	187
1958	154
1959	146
1960	170
1962	155
1963	157
1964	178
1965	148
1966	143
1970	160
1971	184
1973	196
1975	187
1977	188
1978	167
1979	164
1980	147
1981	198
1986	174
1988	158
1989	139
1990	160
1991	147
1992	145
1993	174
1995	147
1997	153
1998	200
1999	154
2000	176
2001	163
2004	170
2005	158
2009	171
2010	157
2012	154
2013	157
2014	139
2015	184
2016	183
2017	175
2018	171
2019	174
2020	157
2021	169
2022	163

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

See the data as a table

Year	Growing-season temperature
1895	19.9 °C
1896	19.6 °C
1897	19.7 °C
1898	19.4 °C
1899	18.9 °C
1900	20.3 °C
1901	20.0 °C
1902	17.9 °C
1903	18.0 °C
1904	18.2 °C
1905	19.4 °C
1906	19.8 °C
1907	17.6 °C
1908	19.1 °C
1909	18.9 °C
1910	19.2 °C
1911	20.8 °C
1912	19.2 °C
1913	20.8 °C
1914	20.6 °C
1915	17.9 °C
1916	18.9 °C
1917	17.6 °C
1918	19.6 °C
1919	19.4 °C
1920	17.9 °C
1921	20.2 °C
1922	19.3 °C
1923	18.6 °C
1924	17.4 °C
1925	19.6 °C
1926	18.4 °C
1927	18.1 °C
1928	18.1 °C
1929	18.4 °C
1930	19.8 °C
1931	19.7 °C
1932	19.2 °C
1933	20.1 °C
1934	21.5 °C
1935	18.3 °C
1936	21.3 °C
1937	20.2 °C
1938	20.0 °C
1939	20.4 °C
1940	18.8 °C
1941	20.4 °C
1942	18.9 °C
1943	18.7 °C
1944	18.7 °C
1945	17.5 °C
1946	18.4 °C
1948	20.1 °C
1949	19.1 °C
1950	17.1 °C
1951	17.4 °C
1952	19.2 °C
1953	19.2 °C
1954	20.4 °C
1955	20.6 °C
1956	19.6 °C
1957	18.9 °C
1958	18.7 °C
1959	19.0 °C
1960	18.8 °C
1962	18.9 °C
1963	19.5 °C
1964	18.9 °C
1965	18.3 °C
1966	17.5 °C
1967	17.4 °C
1968	18.3 °C
1970	19.6 °C
1971	19.0 °C
1973	19.5 °C
1975	18.9 °C
1977	20.4 °C
1978	19.8 °C
1979	18.9 °C
1981	19.8 °C
1984	19.2 °C
1985	20.3 °C
1987	19.9 °C
1988	20.7 °C
1989	17.7 °C
1990	17.9 °C
1991	19.0 °C
1992	16.6 °C
1993	17.5 °C
1994	17.8 °C
1995	17.9 °C
1996	17.2 °C
1997	18.0 °C
1998	19.3 °C
2000	18.9 °C
2001	19.1 °C
2002	18.9 °C
2004	18.5 °C
2008	17.6 °C
2009	17.5 °C
2010	19.6 °C
2011	19.1 °C
2012	19.8 °C
2013	18.1 °C
2014	17.8 °C
2015	18.5 °C
2016	18.9 °C
2017	18.7 °C
2018	19.2 °C
2019	19.0 °C
2020	18.4 °C
2021	19.3 °C
2022	18.9 °C

What this means for you: Since 1895, Mount Ayr's last spring frost has stayed at about the same time of year. Year-to-year swings are large, so keep using the safe date rather than the trend.

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

Nearby towns

Lamoni Lenox Creston Leon Bedford Corning