When to plant in Belvidere, IL
Planting dates worked out from Belvidere's own frost records, not a generic zone chart.
Safe to plant out
May 15
1 year in 10 has a later frost
Average last frost
May 5
about a 50% chance of a later one
Average first fall frost
Oct 7
1 year in 10 by Sep 24
Frost-free days
151
median, 1991–2020
Station used: Marengo · 19.5 km away · station 248 m, town 238 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 20 – Apr 3 | May 15 – May 29 | Jul 9 |
| Sweet pepper | Mar 6 – Mar 20 | May 15 – May 29 | Jul 14 |
| Lettuce (leaf) | Mar 3 – Mar 10 | Apr 7 – Apr 21 | May 17 |
| Peas | — | Apr 3 – May 1 | May 28 |
| Bush beans | — | May 8 – May 29 | Jun 27 |
| Carrot | — | Apr 14 – May 26 | Jun 13 |
| Beet | — | Apr 14 – May 26 | Jun 3 |
| Potato | — | Apr 14 – May 5 | Jun 23 |
| Kale | Feb 27 – Mar 13 | Apr 10 – Apr 24 | May 23 |
| Broccoli | Feb 24 – Mar 10 | Apr 7 – Apr 28 | Jun 6 |
| Cucumber | Apr 17 – Apr 24 | May 15 – May 29 | Jul 4 |
| Summer squash and zucchini | Apr 17 – Apr 24 | May 15 – May 29 | Jun 29 |
| Winter squash | Apr 17 – Apr 24 | May 15 – May 29 | Aug 3 |
| Sweet corn | — | May 8 – May 29 | Jul 7 |
| Onion (from sets) | — | Apr 7 – Apr 28 | Jul 6 |
| Garlic | — | Sep 23 – Oct 21 (fall) | following summer |
| Spinach | — | Apr 3 – May 1 | May 11 |
| Basil | Apr 3 – Apr 17 | May 15 – May 29 | Jul 11 |
Belvidere'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 |
|---|---|
| 1893 | Apr 24 |
| 1894 | Apr 12 |
| 1895 | May 21 |
| 1896 | Apr 10 |
| 1897 | May 1 |
| 1898 | Apr 20 |
| 1899 | Apr 19 |
| 1900 | May 4 |
| 1901 | Apr 21 |
| 1902 | Apr 20 |
| 1903 | May 1 |
| 1904 | Apr 22 |
| 1905 | Apr 22 |
| 1906 | May 9 |
| 1907 | May 20 |
| 1908 | May 3 |
| 1909 | May 4 |
| 1910 | May 14 |
| 1911 | May 3 |
| 1912 | Apr 23 |
| 1913 | May 10 |
| 1914 | Apr 21 |
| 1915 | Apr 13 |
| 1916 | May 18 |
| 1917 | May 23 |
| 1919 | Apr 26 |
| 1920 | May 14 |
| 1921 | Apr 18 |
| 1922 | Apr 29 |
| 1923 | May 13 |
| 1924 | May 1 |
| 1925 | May 25 |
| 1926 | May 4 |
| 1927 | Apr 30 |
| 1928 | May 12 |
| 1929 | May 19 |
| 1930 | Apr 27 |
| 1931 | May 4 |
| 1932 | May 2 |
| 1933 | Apr 27 |
| 1934 | Apr 28 |
| 1935 | May 4 |
| 1936 | Apr 23 |
| 1937 | Apr 16 |
| 1938 | May 13 |
| 1939 | May 12 |
| 1940 | May 11 |
| 1941 | May 10 |
| 1942 | Apr 21 |
| 1943 | May 1 |
| 1944 | May 5 |
| 1945 | Jun 5 |
| 1946 | Apr 27 |
| 1947 | May 10 |
| 1948 | May 8 |
| 1949 | May 28 |
| 1950 | May 2 |
| 1951 | Apr 27 |
| 1952 | Apr 16 |
| 1953 | May 13 |
| 1954 | May 7 |
| 1955 | May 18 |
| 1958 | May 9 |
| 1959 | Apr 22 |
| 1960 | May 12 |
| 1961 | May 26 |
| 1962 | Apr 21 |
| 1963 | May 23 |
| 1964 | Apr 25 |
| 1965 | May 29 |
| 1966 | May 11 |
| 1967 | May 12 |
| 1968 | May 6 |
| 1969 | Apr 30 |
| 1970 | May 7 |
| 1971 | May 12 |
| 1972 | Jun 11 |
| 1973 | May 17 |
| 1974 | May 7 |
| 1975 | Apr 26 |
| 1976 | May 8 |
| 1978 | May 6 |
| 1979 | May 1 |
| 1980 | May 9 |
| 1981 | May 12 |
| 1982 | Apr 28 |
| 1983 | May 10 |
| 1985 | Apr 10 |
| 1986 | May 4 |
| 1987 | May 5 |
| 1988 | Apr 30 |
| 1989 | May 7 |
| 1990 | May 11 |
| 1991 | Apr 23 |
| 1992 | May 27 |
| 1993 | Apr 27 |
| 1995 | Apr 25 |
| 1996 | May 13 |
| 1997 | May 16 |
| 2003 | Apr 23 |
| 2004 | May 3 |
| 2005 | May 4 |
| 2006 | Apr 26 |
| 2010 | May 10 |
| 2011 | May 4 |
| 2012 | Apr 27 |
| 2013 | May 13 |
| 2015 | May 1 |
| 2016 | May 15 |
| 2017 | May 8 |
| 2018 | May 1 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1893 | 173 |
| 1894 | 179 |
| 1895 | 131 |
| 1896 | 179 |
| 1897 | 180 |
| 1898 | 177 |
| 1899 | 163 |
| 1900 | 165 |
| 1901 | 164 |
| 1902 | 176 |
| 1903 | 169 |
| 1904 | 183 |
| 1905 | 172 |
| 1906 | 153 |
| 1907 | 127 |
| 1908 | 148 |
| 1909 | 160 |
| 1910 | 161 |
| 1911 | 173 |
| 1912 | 182 |
| 1913 | 134 |
| 1914 | 186 |
| 1915 | 177 |
| 1916 | 120 |
| 1919 | 167 |
| 1920 | 139 |
| 1921 | 168 |
| 1922 | 170 |
| 1923 | 159 |
| 1924 | 151 |
| 1925 | 136 |
| 1926 | 144 |
| 1927 | 171 |
| 1928 | 134 |
| 1929 | 121 |
| 1930 | 157 |
| 1931 | 180 |
| 1932 | 156 |
| 1933 | 168 |
| 1934 | 182 |
| 1935 | 152 |
| 1936 | 182 |
| 1937 | 163 |
| 1938 | 163 |
| 1939 | 140 |
| 1940 | 137 |
| 1941 | 170 |
| 1942 | 156 |
| 1943 | 147 |
| 1944 | 158 |
| 1945 | 116 |
| 1946 | 156 |
| 1947 | 138 |
| 1948 | 157 |
| 1949 | 118 |
| 1950 | 144 |
| 1951 | 153 |
| 1952 | 169 |
| 1953 | 146 |
| 1954 | 152 |
| 1958 | 144 |
| 1959 | 148 |
| 1960 | 159 |
| 1961 | 124 |
| 1962 | 152 |
| 1963 | 143 |
| 1964 | 155 |
| 1965 | 127 |
| 1966 | 142 |
| 1967 | 152 |
| 1968 | 150 |
| 1969 | 166 |
| 1970 | 149 |
| 1971 | 134 |
| 1973 | 151 |
| 1974 | 137 |
| 1975 | 153 |
| 1976 | 136 |
| 1978 | 154 |
| 1979 | 158 |
| 1980 | 147 |
| 1981 | 142 |
| 1982 | 170 |
| 1983 | 156 |
| 1985 | 178 |
| 1986 | 154 |
| 1987 | 150 |
| 1988 | 157 |
| 1989 | 139 |
| 1990 | 152 |
| 1991 | 150 |
| 1992 | 124 |
| 1993 | 155 |
| 1995 | 150 |
| 1996 | 142 |
| 1997 | 151 |
| 2003 | 160 |
| 2004 | 152 |
| 2005 | 171 |
| 2010 | 146 |
| 2011 | 150 |
| 2012 | 149 |
| 2013 | 159 |
| 2015 | 168 |
| 2016 | 151 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1893 | 16.6 °C |
| 1894 | 18.1 °C |
| 1895 | 18.3 °C |
| 1896 | 18.1 °C |
| 1897 | 17.3 °C |
| 1898 | 17.8 °C |
| 1899 | 18.4 °C |
| 1900 | 18.4 °C |
| 1901 | 18.4 °C |
| 1902 | 16.4 °C |
| 1903 | 16.8 °C |
| 1904 | 16.3 °C |
| 1905 | 17.1 °C |
| 1906 | 18.2 °C |
| 1907 | 15.4 °C |
| 1908 | 17.7 °C |
| 1909 | 16.6 °C |
| 1910 | 17.6 °C |
| 1911 | 18.3 °C |
| 1912 | 17.1 °C |
| 1913 | 17.6 °C |
| 1914 | 17.9 °C |
| 1915 | 16.3 °C |
| 1916 | 17.4 °C |
| 1917 | 15.6 °C |
| 1919 | 17.8 °C |
| 1921 | 19.8 °C |
| 1922 | 18.7 °C |
| 1923 | 17.5 °C |
| 1924 | 15.7 °C |
| 1925 | 18.2 °C |
| 1926 | 16.4 °C |
| 1927 | 16.7 °C |
| 1928 | 16.4 °C |
| 1929 | 16.7 °C |
| 1930 | 18.2 °C |
| 1931 | 18.4 °C |
| 1932 | 17.9 °C |
| 1933 | 18.6 °C |
| 1934 | 19.4 °C |
| 1935 | 16.8 °C |
| 1936 | 18.6 °C |
| 1937 | 17.9 °C |
| 1938 | 17.9 °C |
| 1939 | 18.3 °C |
| 1940 | 17.0 °C |
| 1941 | 18.9 °C |
| 1942 | 17.8 °C |
| 1943 | 17.4 °C |
| 1944 | 18.5 °C |
| 1945 | 16.5 °C |
| 1946 | 17.9 °C |
| 1947 | 17.8 °C |
| 1948 | 18.4 °C |
| 1949 | 18.2 °C |
| 1950 | 16.3 °C |
| 1951 | 16.0 °C |
| 1952 | 18.1 °C |
| 1953 | 17.7 °C |
| 1954 | 17.9 °C |
| 1955 | 19.3 °C |
| 1957 | 17.7 °C |
| 1958 | 17.0 °C |
| 1959 | 18.6 °C |
| 1960 | 17.5 °C |
| 1961 | 16.7 °C |
| 1962 | 17.4 °C |
| 1963 | 17.6 °C |
| 1964 | 18.6 °C |
| 1965 | 17.7 °C |
| 1966 | 16.9 °C |
| 1967 | 16.5 °C |
| 1968 | 17.8 °C |
| 1969 | 17.8 °C |
| 1970 | 18.6 °C |
| 1971 | 18.0 °C |
| 1972 | 17.1 °C |
| 1973 | 17.9 °C |
| 1974 | 17.2 °C |
| 1975 | 17.5 °C |
| 1976 | 17.4 °C |
| 1978 | 18.3 °C |
| 1979 | 17.5 °C |
| 1980 | 17.2 °C |
| 1981 | 16.9 °C |
| 1982 | 16.8 °C |
| 1983 | 17.5 °C |
| 1985 | 17.6 °C |
| 1986 | 17.7 °C |
| 1987 | 18.4 °C |
| 1988 | 18.9 °C |
| 1989 | 16.7 °C |
| 1990 | 17.0 °C |
| 1991 | 18.5 °C |
| 1992 | 15.6 °C |
| 1993 | 16.8 °C |
| 1995 | 18.0 °C |
| 1996 | 16.5 °C |
| 1997 | 16.6 °C |
| 2003 | 17.2 °C |
| 2004 | 16.9 °C |
| 2005 | 18.9 °C |
| 2006 | 18.1 °C |
| 2009 | 16.4 °C |
| 2010 | 19.0 °C |
| 2011 | 17.2 °C |
| 2012 | 18.5 °C |
| 2013 | 17.1 °C |
| 2014 | 16.4 °C |
| 2015 | 17.8 °C |
| 2016 | 18.1 °C |
| 2018 | 17.8 °C |
What this means for you: Since 1893, Belvidere's last spring frost has stayed at about the same time of year. The frost-free season has shrunk by about 1 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Marengo (NOAA GHCN-Daily). Years with too many missing days are left out.