When to plant in Halton Hills, ON
Planting dates worked out from Halton Hills's own frost records, not a generic zone chart.
Safe to plant out
May 8
1 year in 10 has a later frost
Average last frost
Apr 25
about a 50% chance of a later one
Average first fall frost
Oct 20
1 year in 10 by Oct 7
Frost-free days
178
median, 1991–2020
Station used: Toronto Lester B. Pearson Int' · 24.5 km away · station 173 m, town 262 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 15 – Mar 29 | May 10 – May 24 | Jul 4 |
| Sweet pepper | Mar 1 – Mar 15 | May 10 – May 24 | Jul 9 |
| Lettuce (leaf) | Mar 5 – Mar 12 | Apr 9 – Apr 23 | May 19 |
| Peas | — | Apr 9 – May 7 | Jun 3 |
| Bush beans | — | May 4 – May 25 | Jun 23 |
| Carrot | — | Apr 20 – Jun 1 | Jun 19 |
| Beet | — | Apr 20 – Jun 1 | Jun 9 |
| Potato | — | Apr 20 – May 11 | Jun 29 |
| Kale | Mar 5 – Mar 19 | Apr 16 – Apr 30 | May 29 |
| Broccoli | Feb 26 – Mar 12 | Apr 9 – Apr 30 | Jun 8 |
| Cucumber | Apr 12 – Apr 19 | May 10 – May 24 | Jun 29 |
| Summer squash and zucchini | Apr 12 – Apr 19 | May 10 – May 24 | Jun 24 |
| Winter squash | Apr 12 – Apr 19 | May 10 – May 24 | Jul 29 |
| Sweet corn | — | May 4 – May 25 | Jul 3 |
| Onion (from sets) | — | Apr 9 – Apr 30 | Jul 8 |
| Garlic | — | Oct 2 – Oct 30 (fall) | following summer |
| Spinach | — | Apr 9 – May 7 | May 17 |
| Basil | Mar 29 – Apr 12 | May 10 – May 24 | Jul 6 |
Halton Hills'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 | May 25 |
| 1939 | May 18 |
| 1940 | May 5 |
| 1941 | May 13 |
| 1942 | May 10 |
| 1943 | May 1 |
| 1944 | Apr 28 |
| 1945 | May 11 |
| 1946 | May 13 |
| 1947 | May 10 |
| 1948 | Apr 28 |
| 1949 | May 28 |
| 1950 | May 14 |
| 1951 | May 13 |
| 1952 | May 3 |
| 1953 | Apr 29 |
| 1954 | May 4 |
| 1955 | Apr 9 |
| 1956 | May 25 |
| 1957 | May 17 |
| 1958 | May 10 |
| 1959 | May 16 |
| 1960 | May 2 |
| 1961 | May 2 |
| 1962 | May 10 |
| 1963 | May 24 |
| 1964 | Apr 26 |
| 1965 | Apr 29 |
| 1966 | May 11 |
| 1967 | May 23 |
| 1968 | May 7 |
| 1969 | May 26 |
| 1970 | May 7 |
| 1971 | May 1 |
| 1972 | May 12 |
| 1973 | May 19 |
| 1974 | May 8 |
| 1975 | Apr 28 |
| 1976 | May 7 |
| 1977 | May 8 |
| 1978 | May 4 |
| 1979 | May 5 |
| 1980 | Apr 24 |
| 1981 | May 18 |
| 1982 | Apr 29 |
| 1983 | May 18 |
| 1984 | May 14 |
| 1985 | May 8 |
| 1986 | May 4 |
| 1987 | May 8 |
| 1988 | Apr 25 |
| 1989 | Apr 28 |
| 1990 | May 3 |
| 1991 | Apr 12 |
| 1992 | Apr 15 |
| 1994 | Apr 23 |
| 1995 | May 8 |
| 1996 | May 13 |
| 1997 | Apr 21 |
| 1998 | Apr 28 |
| 1999 | Apr 24 |
| 2000 | Apr 13 |
| 2001 | Apr 29 |
| 2002 | May 20 |
| 2003 | Apr 23 |
| 2004 | May 4 |
| 2005 | May 3 |
| 2006 | Apr 29 |
| 2007 | Apr 14 |
| 2008 | Apr 30 |
| 2009 | Apr 13 |
| 2010 | Apr 10 |
| 2011 | Apr 22 |
| 2012 | Apr 29 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1938 | 129 |
| 1940 | 163 |
| 1941 | 156 |
| 1942 | 140 |
| 1943 | 139 |
| 1944 | 148 |
| 1945 | 141 |
| 1946 | 159 |
| 1947 | 138 |
| 1948 | 172 |
| 1949 | 119 |
| 1950 | 153 |
| 1951 | 138 |
| 1952 | 153 |
| 1953 | 146 |
| 1954 | 155 |
| 1955 | 195 |
| 1956 | 117 |
| 1957 | 133 |
| 1958 | 148 |
| 1959 | 123 |
| 1960 | 172 |
| 1961 | 154 |
| 1962 | 166 |
| 1963 | 158 |
| 1964 | 141 |
| 1965 | 149 |
| 1966 | 138 |
| 1967 | 142 |
| 1968 | 151 |
| 1969 | 135 |
| 1970 | 150 |
| 1971 | 185 |
| 1972 | 149 |
| 1973 | 120 |
| 1974 | 136 |
| 1975 | 156 |
| 1976 | 156 |
| 1977 | 157 |
| 1978 | 156 |
| 1979 | 137 |
| 1980 | 155 |
| 1981 | 134 |
| 1982 | 169 |
| 1983 | 154 |
| 1984 | 143 |
| 1985 | 161 |
| 1986 | 157 |
| 1987 | 147 |
| 1988 | 165 |
| 1989 | 151 |
| 1990 | 168 |
| 1991 | 169 |
| 1992 | 185 |
| 1994 | 170 |
| 1995 | 178 |
| 1996 | 154 |
| 1997 | 179 |
| 1998 | 187 |
| 1999 | 165 |
| 2000 | 198 |
| 2001 | 160 |
| 2002 | 155 |
| 2003 | 182 |
| 2004 | 187 |
| 2005 | 177 |
| 2006 | 166 |
| 2007 | 196 |
| 2008 | 174 |
| 2009 | 180 |
| 2010 | 194 |
| 2011 | 187 |
| 2012 | 166 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1938 | 16.0 °C |
| 1940 | 14.6 °C |
| 1941 | 16.7 °C |
| 1942 | 15.8 °C |
| 1943 | 15.1 °C |
| 1944 | 16.1 °C |
| 1945 | 14.9 °C |
| 1946 | 14.9 °C |
| 1947 | 15.4 °C |
| 1948 | 16.1 °C |
| 1949 | 16.9 °C |
| 1950 | 14.4 °C |
| 1951 | 15.6 °C |
| 1952 | 16.5 °C |
| 1953 | 15.9 °C |
| 1954 | 15.4 °C |
| 1955 | 17.7 °C |
| 1956 | 14.1 °C |
| 1957 | 15.8 °C |
| 1958 | 15.7 °C |
| 1959 | 17.7 °C |
| 1960 | 16.3 °C |
| 1961 | 15.9 °C |
| 1962 | 16.1 °C |
| 1963 | 15.4 °C |
| 1964 | 14.8 °C |
| 1965 | 14.0 °C |
| 1966 | 14.4 °C |
| 1967 | 14.1 °C |
| 1968 | 14.7 °C |
| 1969 | 15.1 °C |
| 1970 | 15.2 °C |
| 1971 | 14.8 °C |
| 1972 | 14.2 °C |
| 1973 | 15.7 °C |
| 1974 | 14.6 °C |
| 1975 | 15.2 °C |
| 1976 | 14.7 °C |
| 1977 | 15.4 °C |
| 1978 | 14.8 °C |
| 1979 | 14.7 °C |
| 1980 | 15.3 °C |
| 1981 | 15.2 °C |
| 1982 | 14.6 °C |
| 1983 | 15.7 °C |
| 1984 | 15.1 °C |
| 1985 | 15.3 °C |
| 1986 | 15.4 °C |
| 1987 | 16.8 °C |
| 1988 | 16.2 °C |
| 1989 | 15.6 °C |
| 1990 | 16.0 °C |
| 1991 | 17.1 °C |
| 1992 | 14.2 °C |
| 1994 | 15.7 °C |
| 1995 | 15.9 °C |
| 1996 | 15.2 °C |
| 1997 | 15.1 °C |
| 1998 | 17.6 °C |
| 1999 | 17.8 °C |
| 2000 | 16.0 °C |
| 2001 | 17.3 °C |
| 2002 | 17.4 °C |
| 2003 | 16.2 °C |
| 2004 | 16.1 °C |
| 2005 | 18.0 °C |
| 2006 | 17.1 °C |
| 2007 | 17.2 °C |
| 2008 | 16.5 °C |
| 2009 | 15.9 °C |
| 2010 | 18.0 °C |
| 2011 | 17.4 °C |
| 2012 | 17.8 °C |
What this means for you: Since 1938, Halton Hills's last spring frost has come about 3 days earlier per decade, on average. The frost-free season has grown by about 5 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Toronto Lester B. Pearson Int' (NOAA GHCN-Daily, from Environment and Climate Change Canada). Years with too many missing days are left out.