When to plant in Quincy, IL
Planting dates worked out from Quincy's own frost records, not a generic zone chart.
Safe to plant out
Apr 18
1 year in 10 has a later frost
Average last frost
Apr 7
about a 50% chance of a later one
Average first fall frost
Oct 28
1 year in 10 by Oct 17
Frost-free days
202
median, 1991–2020
Station used: Quincy Dam 21 · 3.9 km away · station 147 m, town 173 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 | Feb 21 – Mar 7 | Apr 18 – May 2 | Jun 12 |
| Sweet pepper | Feb 7 – Feb 21 | Apr 18 – May 2 | Jun 17 |
| Lettuce (leaf) | Feb 12 – Feb 19 | Mar 19 – Apr 2 | Apr 28 |
| Peas | — | Mar 19 – Apr 16 | May 13 |
| Bush beans | — | Apr 11 – May 2 | May 31 |
| Carrot | — | Mar 28 – May 9 | May 27 |
| Beet | — | Mar 28 – May 9 | May 17 |
| Potato | — | Mar 28 – Apr 18 | Jun 6 |
| Kale | Feb 12 – Feb 26 | Mar 26 – Apr 9 | May 8 |
| Broccoli | Feb 5 – Feb 19 | Mar 19 – Apr 9 | May 18 |
| Cucumber | Mar 21 – Mar 28 | Apr 18 – May 2 | Jun 7 |
| Summer squash and zucchini | Mar 21 – Mar 28 | Apr 18 – May 2 | Jun 2 |
| Winter squash | Mar 21 – Mar 28 | Apr 18 – May 2 | Jul 7 |
| Sweet corn | — | Apr 11 – May 2 | Jun 10 |
| Onion (from sets) | — | Mar 19 – Apr 9 | Jun 17 |
| Garlic | — | Oct 14 – Nov 11 (fall) | following summer |
| Spinach | — | Mar 19 – Apr 16 | Apr 26 |
| Basil | Mar 7 – Mar 21 | Apr 18 – May 2 | Jun 14 |
Quincy'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 |
|---|---|
| 1938 | Apr 10 |
| 1939 | Apr 13 |
| 1940 | Apr 20 |
| 1941 | Apr 2 |
| 1942 | Apr 11 |
| 1944 | Apr 5 |
| 1945 | Mar 13 |
| 1946 | Mar 11 |
| 1947 | Apr 2 |
| 1977 | Apr 7 |
| 1978 | Mar 28 |
| 1979 | Apr 7 |
| 1980 | Apr 15 |
| 1981 | Apr 7 |
| 1982 | Apr 21 |
| 1983 | Apr 21 |
| 1988 | Apr 25 |
| 1990 | Apr 13 |
| 1991 | Apr 1 |
| 1992 | Apr 4 |
| 1993 | Apr 18 |
| 1996 | Apr 11 |
| 1997 | Apr 18 |
| 1998 | Mar 25 |
| 1999 | Mar 27 |
| 2000 | Apr 9 |
| 2001 | Apr 17 |
| 2002 | Apr 6 |
| 2003 | Apr 11 |
| 2005 | Mar 18 |
| 2006 | Apr 10 |
| 2007 | Apr 14 |
| 2008 | Apr 3 |
| 2009 | Apr 10 |
| 2010 | Mar 27 |
| 2013 | Apr 3 |
| 2014 | Apr 16 |
| 2016 | Apr 14 |
| 2017 | Mar 23 |
| 2018 | Apr 19 |
| 2020 | Apr 19 |
| 2021 | Apr 23 |
| 2022 | Apr 20 |
| 2024 | Mar 29 |
| 2025 | Apr 9 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1938 | 211 |
| 1939 | 183 |
| 1940 | 200 |
| 1941 | 208 |
| 1942 | 169 |
| 1944 | 232 |
| 1945 | 235 |
| 1946 | 246 |
| 1947 | 222 |
| 1977 | 216 |
| 1978 | 209 |
| 1979 | 180 |
| 1980 | 180 |
| 1981 | 198 |
| 1982 | 182 |
| 1988 | 180 |
| 1990 | 188 |
| 1991 | 200 |
| 1992 | 195 |
| 1996 | 190 |
| 1997 | 186 |
| 1998 | 225 |
| 1999 | 211 |
| 2000 | 180 |
| 2001 | 182 |
| 2002 | 208 |
| 2003 | 209 |
| 2005 | 222 |
| 2006 | 196 |
| 2007 | 201 |
| 2008 | 207 |
| 2009 | 190 |
| 2010 | 215 |
| 2013 | 204 |
| 2014 | 198 |
| 2016 | 212 |
| 2017 | 219 |
| 2018 | 202 |
| 2021 | 193 |
| 2022 | 180 |
| 2024 | 238 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1938 | 20.9 °C |
| 1939 | 21.0 °C |
| 1940 | 20.0 °C |
| 1941 | 22.6 °C |
| 1942 | 20.6 °C |
| 1943 | 21.2 °C |
| 1944 | 20.6 °C |
| 1945 | 19.5 °C |
| 1946 | 20.1 °C |
| 1947 | 20.6 °C |
| 1977 | 20.9 °C |
| 1978 | 19.7 °C |
| 1979 | 19.2 °C |
| 1980 | 20.2 °C |
| 1981 | 19.5 °C |
| 1982 | 18.6 °C |
| 1983 | 19.8 °C |
| 1988 | 20.8 °C |
| 1990 | 19.7 °C |
| 1991 | 21.2 °C |
| 1992 | 18.6 °C |
| 1996 | 19.3 °C |
| 1997 | 19.1 °C |
| 1998 | 21.3 °C |
| 1999 | 20.7 °C |
| 2000 | 20.4 °C |
| 2001 | 20.8 °C |
| 2002 | 20.8 °C |
| 2005 | 21.4 °C |
| 2006 | 20.8 °C |
| 2007 | 21.3 °C |
| 2008 | 19.6 °C |
| 2009 | 19.3 °C |
| 2010 | 21.8 °C |
| 2012 | 21.7 °C |
| 2016 | 21.4 °C |
| 2017 | 20.8 °C |
| 2018 | 21.5 °C |
| 2021 | 20.5 °C |
| 2022 | 20.1 °C |
| 2024 | 20.9 °C |
| 2025 | 20.7 °C |
What this means for you: Since 1938, Quincy'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 Quincy Dam 21 (NOAA GHCN-Daily). Years with too many missing days are left out.