When to plant in Leon, IA
Planting dates worked out from Leon's own frost records, not a generic zone chart.
Safe to plant out
May 16
1 year in 10 has a later frost
Average last frost
May 2
about a 50% chance of a later one
Average first fall frost
Oct 4
1 year in 10 by Sep 22
Frost-free days
154
median, 1991–2020
Station used: Leon 6 Ese · 8.8 km away · station 305 m, town 343 m. How we match towns to stations
This season
Plan your garden.
Planting dates for common crops
| Crop | Start indoors | Plant out or sow | Harvest from |
|---|---|---|---|
| Tomato | Mar 21 – Apr 4 | May 16 – May 30 | Jul 10 |
| Sweet pepper | Mar 7 – Mar 21 | May 16 – May 30 | Jul 15 |
| Lettuce (leaf) | Feb 28 – Mar 7 | Apr 4 – Apr 18 | May 14 |
| Peas | — | Mar 26 – Apr 23 | May 20 |
| Bush beans | — | May 9 – May 30 | Jun 28 |
| Carrot | — | Apr 11 – May 23 | Jun 10 |
| Beet | — | Apr 4 – May 16 | May 24 |
| Potato | — | Apr 11 – May 2 | Jun 20 |
| Kale | Feb 21 – Mar 7 | Apr 4 – Apr 18 | May 17 |
| Broccoli | Feb 21 – Mar 7 | Apr 4 – Apr 25 | Jun 3 |
| Cucumber | Apr 18 – Apr 25 | May 16 – May 30 | Jul 5 |
| Summer squash and zucchini | Apr 18 – Apr 25 | May 16 – May 30 | Jun 30 |
| Winter squash | Apr 18 – Apr 25 | May 16 – May 30 | Aug 4 |
| Sweet corn | — | May 9 – May 30 | Jul 8 |
| Onion (from sets) | — | Apr 4 – Apr 25 | Jul 3 |
| Garlic | — | Sep 20 – Oct 18 (fall) | following summer |
| Spinach | — | Mar 26 – Apr 23 | May 3 |
| Basil | Apr 4 – Apr 18 | May 16 – May 30 | Jul 12 |
Leon'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 |
|---|---|
| 1962 | Apr 16 |
| 1963 | May 23 |
| 1964 | Apr 9 |
| 1965 | Apr 19 |
| 1966 | May 10 |
| 1967 | May 2 |
| 1968 | Apr 25 |
| 1969 | Apr 6 |
| 1970 | May 2 |
| 1971 | Apr 7 |
| 1972 | Apr 9 |
| 1973 | Apr 16 |
| 1974 | Apr 15 |
| 1975 | Apr 20 |
| 1976 | May 3 |
| 1977 | Apr 6 |
| 1978 | Apr 21 |
| 1979 | Apr 28 |
| 1981 | May 11 |
| 1982 | Apr 23 |
| 1983 | May 9 |
| 1984 | May 8 |
| 1985 | Apr 15 |
| 1986 | Apr 22 |
| 1987 | Apr 28 |
| 1988 | Apr 29 |
| 1989 | May 12 |
| 1990 | May 11 |
| 1991 | Apr 25 |
| 1992 | May 28 |
| 1993 | Apr 23 |
| 1994 | May 8 |
| 1995 | Apr 26 |
| 1996 | May 1 |
| 1997 | May 16 |
| 1998 | Apr 20 |
| 1999 | Apr 19 |
| 2000 | May 14 |
| 2001 | Apr 25 |
| 2002 | May 19 |
| 2003 | Apr 23 |
| 2004 | May 4 |
| 2005 | May 5 |
| 2006 | May 7 |
| 2007 | Apr 17 |
| 2008 | May 5 |
| 2009 | Apr 16 |
| 2010 | May 10 |
| 2011 | May 5 |
| 2012 | Apr 22 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1962 | 190 |
| 1963 | 158 |
| 1964 | 182 |
| 1965 | 157 |
| 1966 | 153 |
| 1967 | 149 |
| 1968 | 161 |
| 1969 | 190 |
| 1970 | 160 |
| 1971 | 206 |
| 1972 | 173 |
| 1973 | 200 |
| 1974 | 168 |
| 1975 | 164 |
| 1976 | 155 |
| 1977 | 188 |
| 1978 | 187 |
| 1979 | 177 |
| 1981 | 129 |
| 1982 | 150 |
| 1983 | 134 |
| 1984 | 130 |
| 1985 | 164 |
| 1986 | 138 |
| 1987 | 157 |
| 1988 | 156 |
| 1989 | 133 |
| 1990 | 142 |
| 1991 | 146 |
| 1992 | 123 |
| 1993 | 158 |
| 1994 | 154 |
| 1995 | 148 |
| 1996 | 159 |
| 1997 | 150 |
| 1998 | 170 |
| 1999 | 154 |
| 2000 | 144 |
| 2001 | 152 |
| 2002 | 140 |
| 2003 | 158 |
| 2004 | 150 |
| 2005 | 154 |
| 2006 | 157 |
| 2007 | 188 |
| 2008 | 163 |
| 2009 | 174 |
| 2010 | 146 |
| 2011 | 148 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1962 | 19.2 °C |
| 1963 | 19.1 °C |
| 1964 | 19.6 °C |
| 1965 | 18.7 °C |
| 1966 | 18.3 °C |
| 1967 | 18.1 °C |
| 1968 | 19.0 °C |
| 1969 | 19.3 °C |
| 1970 | 19.7 °C |
| 1971 | 19.8 °C |
| 1972 | 19.5 °C |
| 1973 | 19.1 °C |
| 1974 | 19.1 °C |
| 1975 | 19.6 °C |
| 1976 | 19.8 °C |
| 1978 | 19.9 °C |
| 1979 | 19.1 °C |
| 1981 | 19.4 °C |
| 1982 | 18.3 °C |
| 1983 | 19.8 °C |
| 1984 | 18.6 °C |
| 1985 | 19.1 °C |
| 1986 | 19.8 °C |
| 1987 | 20.1 °C |
| 1989 | 17.4 °C |
| 1990 | 18.1 °C |
| 1991 | 19.1 °C |
| 1992 | 16.3 °C |
| 1993 | 17.1 °C |
| 1994 | 17.3 °C |
| 1995 | 17.3 °C |
| 1996 | 16.8 °C |
| 1997 | 17.0 °C |
| 1998 | 19.0 °C |
| 1999 | 18.1 °C |
| 2000 | 18.5 °C |
| 2001 | 18.4 °C |
| 2002 | 18.4 °C |
| 2003 | 17.8 °C |
| 2004 | 18.2 °C |
| 2005 | 19.0 °C |
| 2006 | 18.9 °C |
| 2007 | 18.9 °C |
| 2008 | 17.4 °C |
| 2009 | 17.1 °C |
| 2010 | 19.2 °C |
| 2011 | 18.4 °C |
| 2012 | 19.4 °C |
What this means for you: Since 1962, Leon's last spring frost has come about 2 days later per decade, on average. The frost-free season has shrunk by about 4 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Leon 6 Ese (NOAA GHCN-Daily). Years with too many missing days are left out.