When to plant in Manhattan, IL
Planting dates worked out from Manhattan's own frost records, not a generic zone chart.
Safe to plant out
Apr 30
1 year in 10 has a later frost
Average last frost
Apr 16
about a 50% chance of a later one
Average first fall frost
Oct 19
1 year in 10 by Oct 6
Frost-free days
184
median, 1991–2020
Station used: Joliet Brandon Road Lock/dam · 13.3 km away · station 166 m, town 208 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 5 – Mar 19 | Apr 30 – May 14 | Jun 24 |
| Sweet pepper | Feb 19 – Mar 5 | Apr 30 – May 14 | Jun 29 |
| Lettuce (leaf) | Feb 21 – Feb 28 | Mar 28 – Apr 11 | May 7 |
| Peas | — | Mar 28 – Apr 25 | May 22 |
| Bush beans | — | Apr 23 – May 14 | Jun 12 |
| Carrot | — | Apr 6 – May 18 | Jun 5 |
| Beet | — | Apr 6 – May 18 | May 26 |
| Potato | — | Apr 6 – Apr 27 | Jun 15 |
| Kale | Feb 21 – Mar 7 | Apr 4 – Apr 18 | May 17 |
| Broccoli | Feb 14 – Feb 28 | Mar 28 – Apr 18 | May 27 |
| Cucumber | Apr 2 – Apr 9 | Apr 30 – May 14 | Jun 19 |
| Summer squash and zucchini | Apr 2 – Apr 9 | Apr 30 – May 14 | Jun 14 |
| Winter squash | Apr 2 – Apr 9 | Apr 30 – May 14 | Jul 19 |
| Sweet corn | — | Apr 23 – May 14 | Jun 22 |
| Onion (from sets) | — | Mar 28 – Apr 18 | Jun 26 |
| Garlic | — | Oct 5 – Nov 2 (fall) | following summer |
| Spinach | — | Mar 28 – Apr 25 | May 5 |
| Basil | Mar 19 – Apr 2 | Apr 30 – May 14 | Jun 26 |
Manhattan'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 |
|---|---|
| 1976 | May 7 |
| 1977 | May 10 |
| 1978 | May 3 |
| 1979 | May 1 |
| 1980 | Apr 26 |
| 1981 | May 12 |
| 1983 | May 9 |
| 1984 | Apr 22 |
| 1985 | May 4 |
| 1986 | Apr 23 |
| 1987 | Apr 9 |
| 1988 | Apr 20 |
| 1990 | Apr 19 |
| 1991 | Apr 3 |
| 1992 | Apr 30 |
| 1993 | Apr 22 |
| 1994 | Apr 8 |
| 1995 | Apr 6 |
| 1996 | Apr 11 |
| 1997 | Apr 19 |
| 1998 | Apr 6 |
| 1999 | Mar 28 |
| 2000 | Apr 13 |
| 2001 | Apr 19 |
| 2002 | Apr 6 |
| 2003 | Apr 11 |
| 2004 | Apr 14 |
| 2005 | May 4 |
| 2006 | Apr 10 |
| 2007 | Apr 16 |
| 2008 | Apr 16 |
| 2009 | Apr 12 |
| 2010 | Apr 10 |
| 2011 | Apr 22 |
| 2012 | Apr 13 |
| 2013 | Apr 21 |
| 2014 | Apr 17 |
| 2015 | Apr 27 |
| 2016 | Apr 13 |
| 2017 | Apr 2 |
| 2018 | Apr 29 |
| 2019 | Apr 30 |
| 2020 | May 10 |
| 2021 | Apr 23 |
| 2022 | Apr 27 |
| 2023 | Apr 24 |
| 2024 | Apr 24 |
| 2025 | Apr 9 |
| 2026 | May 3 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1976 | 163 |
| 1977 | 154 |
| 1978 | 157 |
| 1979 | 164 |
| 1980 | 161 |
| 1981 | 159 |
| 1983 | 136 |
| 1985 | 154 |
| 1986 | 192 |
| 1988 | 174 |
| 1990 | 182 |
| 1991 | 185 |
| 1992 | 169 |
| 1993 | 170 |
| 1994 | 202 |
| 1995 | 210 |
| 1996 | 190 |
| 1997 | 190 |
| 1998 | 213 |
| 1999 | 209 |
| 2001 | 170 |
| 2002 | 196 |
| 2003 | 173 |
| 2004 | 185 |
| 2005 | 171 |
| 2006 | 184 |
| 2007 | 194 |
| 2008 | 194 |
| 2009 | 181 |
| 2010 | 178 |
| 2011 | 179 |
| 2012 | 175 |
| 2013 | 183 |
| 2014 | 195 |
| 2015 | 173 |
| 2017 | 218 |
| 2018 | 169 |
| 2019 | 165 |
| 2020 | 167 |
| 2022 | 174 |
| 2023 | 170 |
| 2024 | 186 |
| 2025 | 198 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1976 | 18.2 °C |
| 1977 | 19.4 °C |
| 1978 | 18.5 °C |
| 1979 | 17.8 °C |
| 1980 | 18.3 °C |
| 1981 | 18.2 °C |
| 1983 | 18.1 °C |
| 1984 | 17.9 °C |
| 1985 | 18.1 °C |
| 1986 | 18.8 °C |
| 1988 | 19.9 °C |
| 1990 | 18.1 °C |
| 1991 | 20.3 °C |
| 1992 | 16.8 °C |
| 1993 | 17.9 °C |
| 1994 | 18.1 °C |
| 1995 | 18.8 °C |
| 1996 | 17.5 °C |
| 1997 | 17.3 °C |
| 1998 | 19.8 °C |
| 1999 | 19.3 °C |
| 2000 | 18.6 °C |
| 2001 | 19.2 °C |
| 2002 | 19.4 °C |
| 2003 | 18.4 °C |
| 2004 | 18.4 °C |
| 2005 | 19.5 °C |
| 2006 | 18.6 °C |
| 2007 | 19.2 °C |
| 2008 | 18.1 °C |
| 2009 | 17.3 °C |
| 2010 | 20.0 °C |
| 2011 | 18.7 °C |
| 2012 | 19.7 °C |
| 2013 | 18.3 °C |
| 2014 | 17.9 °C |
| 2015 | 18.6 °C |
| 2016 | 19.2 °C |
| 2017 | 18.5 °C |
| 2018 | 18.9 °C |
| 2019 | 18.5 °C |
| 2020 | 18.2 °C |
| 2022 | 18.3 °C |
| 2023 | 18.5 °C |
| 2024 | 19.1 °C |
| 2025 | 19.2 °C |
| 2026 | 19.5 °C |
What this means for you: Since 1976, Manhattan's last spring frost has come about 2 days earlier per decade, on average. The frost-free season has grown 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 Joliet Brandon Road Lock/dam (NOAA GHCN-Daily). Years with too many missing days are left out.