When to plant in Monona, WI
Planting dates worked out from Monona's own frost records, not a generic zone chart.
Safe to plant out
May 23
1 year in 10 has a later frost
Average last frost
May 7
about a 50% chance of a later one
Average first fall frost
Oct 5
1 year in 10 by Sep 22
Frost-free days
150
median, 1991–2020
Station used: Uw Arboretum - Madison · 8.0 km away · station 265 m, town 268 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 28 – Apr 11 | May 23 – Jun 6 | Jul 17 |
| Sweet pepper | Mar 14 – Mar 28 | May 23 – Jun 6 | Jul 22 |
| Lettuce (leaf) | Mar 5 – Mar 12 | Apr 9 – Apr 23 | May 19 |
| Peas | — | Apr 7 – May 5 | Jun 1 |
| Bush beans | — | May 16 – Jun 6 | Jul 5 |
| Carrot | — | Apr 17 – May 29 | Jun 16 |
| Beet | — | Apr 17 – May 29 | Jun 6 |
| Potato | — | Apr 17 – May 8 | Jun 26 |
| Kale | Mar 3 – Mar 17 | Apr 14 – Apr 28 | May 27 |
| Broccoli | Feb 26 – Mar 12 | Apr 9 – Apr 30 | Jun 8 |
| Cucumber | Apr 25 – May 2 | May 23 – Jun 6 | Jul 12 |
| Summer squash and zucchini | Apr 25 – May 2 | May 23 – Jun 6 | Jul 7 |
| Winter squash | Apr 25 – May 2 | May 23 – Jun 6 | Aug 11 |
| Sweet corn | — | May 16 – Jun 6 | Jul 15 |
| Onion (from sets) | — | Apr 9 – Apr 30 | Jul 8 |
| Garlic | — | Sep 21 – Oct 19 (fall) | following summer |
| Spinach | — | Apr 7 – May 5 | May 15 |
| Basil | Apr 11 – Apr 25 | May 23 – Jun 6 | Jul 19 |
Monona'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 |
|---|---|
| 1972 | May 10 |
| 1973 | May 17 |
| 1974 | May 13 |
| 1975 | May 1 |
| 1976 | May 25 |
| 1977 | Jun 9 |
| 1978 | May 6 |
| 1979 | Jun 25 |
| 1980 | Jun 10 |
| 1981 | May 20 |
| 1982 | Apr 30 |
| 1983 | May 26 |
| 1984 | May 31 |
| 1985 | May 23 |
| 1986 | May 3 |
| 1987 | May 5 |
| 1988 | May 25 |
| 1989 | May 12 |
| 1990 | May 11 |
| 1991 | May 4 |
| 1992 | Jun 21 |
| 1993 | Apr 27 |
| 1994 | May 27 |
| 1995 | May 22 |
| 1996 | May 30 |
| 1997 | May 22 |
| 1998 | Apr 29 |
| 1999 | May 1 |
| 2000 | Apr 22 |
| 2001 | Apr 19 |
| 2002 | May 21 |
| 2003 | May 3 |
| 2004 | May 4 |
| 2006 | May 6 |
| 2007 | Apr 17 |
| 2008 | Apr 30 |
| 2009 | Apr 22 |
| 2010 | May 10 |
| 2011 | May 5 |
| 2012 | Apr 29 |
| 2013 | May 13 |
| 2014 | Apr 23 |
| 2015 | Apr 28 |
| 2016 | May 15 |
| 2017 | May 7 |
| 2018 | Apr 29 |
| 2019 | May 12 |
| 2020 | May 13 |
| 2021 | May 11 |
| 2022 | Apr 28 |
| 2023 | Apr 26 |
| 2024 | Apr 25 |
| 2025 | May 9 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1972 | 149 |
| 1973 | 152 |
| 1974 | 113 |
| 1975 | 130 |
| 1977 | 114 |
| 1978 | 144 |
| 1979 | 51 |
| 1981 | 125 |
| 1982 | 144 |
| 1983 | 120 |
| 1985 | 124 |
| 1986 | 155 |
| 1987 | 148 |
| 1988 | 103 |
| 1989 | 134 |
| 1990 | 142 |
| 1991 | 138 |
| 1993 | 149 |
| 1994 | 134 |
| 1995 | 123 |
| 1996 | 125 |
| 1997 | 124 |
| 1998 | 162 |
| 1999 | 153 |
| 2000 | 167 |
| 2001 | 169 |
| 2002 | 138 |
| 2003 | 150 |
| 2006 | 158 |
| 2007 | 150 |
| 2008 | 156 |
| 2009 | 170 |
| 2010 | 146 |
| 2011 | 149 |
| 2012 | 142 |
| 2013 | 154 |
| 2014 | 170 |
| 2015 | 171 |
| 2016 | 150 |
| 2017 | 174 |
| 2018 | 166 |
| 2019 | 152 |
| 2020 | 141 |
| 2021 | 164 |
| 2022 | 162 |
| 2023 | 167 |
| 2024 | 173 |
| 2025 | 152 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1972 | 16.0 °C |
| 1973 | 16.6 °C |
| 1974 | 15.6 °C |
| 1975 | 16.0 °C |
| 1977 | 16.9 °C |
| 1978 | 17.0 °C |
| 1979 | 15.4 °C |
| 1981 | 16.3 °C |
| 1982 | 15.4 °C |
| 1983 | 16.5 °C |
| 1984 | 15.8 °C |
| 1985 | 17.1 °C |
| 1986 | 16.9 °C |
| 1987 | 17.9 °C |
| 1988 | 18.3 °C |
| 1989 | 16.1 °C |
| 1990 | 16.7 °C |
| 1991 | 17.9 °C |
| 1992 | 15.0 °C |
| 1993 | 15.6 °C |
| 1994 | 16.3 °C |
| 1995 | 16.7 °C |
| 1997 | 14.8 °C |
| 1998 | 17.0 °C |
| 1999 | 17.3 °C |
| 2000 | 16.6 °C |
| 2001 | 17.3 °C |
| 2002 | 17.1 °C |
| 2003 | 16.4 °C |
| 2006 | 17.0 °C |
| 2007 | 17.4 °C |
| 2008 | 16.6 °C |
| 2009 | 16.1 °C |
| 2010 | 18.2 °C |
| 2011 | 16.9 °C |
| 2012 | 18.1 °C |
| 2013 | 16.6 °C |
| 2014 | 16.3 °C |
| 2015 | 17.3 °C |
| 2016 | 17.6 °C |
| 2017 | 17.0 °C |
| 2018 | 17.3 °C |
| 2019 | 17.0 °C |
| 2020 | 17.5 °C |
| 2021 | 18.4 °C |
| 2022 | 17.4 °C |
| 2023 | 18.1 °C |
| 2024 | 18.1 °C |
| 2025 | 17.5 °C |
What this means for you: Since 1972, Monona's last spring frost has come about 4 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 Uw Arboretum - Madison (NOAA GHCN-Daily). Years with too many missing days are left out.