When to plant in Acton, ON
Planting dates worked out from Acton's own frost records, not a generic zone chart.
Safe to plant out
May 18
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 11
1 year in 10 by Sep 26
Frost-free days
157
median, 1991–2020
Station used: Fergus Shand Dam · 26.0 km away · station 418 m, town 349 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 23 – Apr 6 | May 18 – Jun 1 | Jul 12 |
| Sweet pepper | Mar 9 – Mar 23 | May 18 – Jun 1 | Jul 17 |
| Lettuce (leaf) | Mar 14 – Mar 21 | Apr 18 – May 2 | May 28 |
| Peas | — | Apr 18 – May 16 | Jun 12 |
| Bush beans | — | May 11 – Jun 1 | Jun 30 |
| Carrot | — | Apr 25 – Jun 6 | Jun 24 |
| Beet | — | Apr 25 – Jun 6 | Jun 14 |
| Potato | — | Apr 25 – May 16 | Jul 4 |
| Kale | Mar 14 – Mar 28 | Apr 25 – May 9 | Jun 7 |
| Broccoli | Mar 7 – Mar 21 | Apr 18 – May 9 | Jun 17 |
| Cucumber | Apr 20 – Apr 27 | May 18 – Jun 1 | Jul 7 |
| Summer squash and zucchini | Apr 20 – Apr 27 | May 18 – Jun 1 | Jul 2 |
| Winter squash | Apr 20 – Apr 27 | May 18 – Jun 1 | Aug 6 |
| Sweet corn | — | May 11 – Jun 1 | Jul 10 |
| Onion (from sets) | — | Apr 18 – May 9 | Jul 17 |
| Garlic | — | Sep 27 – Oct 25 (fall) | following summer |
| Spinach | — | Apr 18 – May 16 | May 26 |
| Basil | Apr 6 – Apr 20 | May 18 – Jun 1 | Jul 14 |
Acton'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 |
|---|---|
| 1940 | May 10 |
| 1941 | Jun 8 |
| 1943 | May 14 |
| 1944 | May 5 |
| 1945 | May 11 |
| 1946 | May 13 |
| 1947 | May 11 |
| 1948 | May 9 |
| 1949 | May 11 |
| 1950 | May 8 |
| 1951 | May 13 |
| 1952 | May 4 |
| 1953 | May 14 |
| 1954 | May 28 |
| 1955 | Apr 8 |
| 1956 | May 25 |
| 1957 | Jun 3 |
| 1958 | May 27 |
| 1959 | May 16 |
| 1960 | May 2 |
| 1961 | May 26 |
| 1962 | May 9 |
| 1963 | May 26 |
| 1964 | Jun 5 |
| 1965 | May 30 |
| 1966 | May 30 |
| 1967 | May 23 |
| 1968 | May 7 |
| 1969 | May 1 |
| 1970 | May 8 |
| 1972 | Jun 11 |
| 1973 | May 19 |
| 1974 | May 8 |
| 1975 | Apr 28 |
| 1976 | May 8 |
| 1977 | May 9 |
| 1978 | May 4 |
| 1979 | May 6 |
| 1980 | May 10 |
| 1981 | May 17 |
| 1982 | Apr 28 |
| 1983 | May 18 |
| 1984 | May 14 |
| 1985 | May 8 |
| 1986 | May 4 |
| 1987 | May 1 |
| 1988 | May 14 |
| 1989 | Apr 28 |
| 1990 | May 11 |
| 1991 | Apr 23 |
| 1992 | May 6 |
| 1993 | May 26 |
| 1994 | May 13 |
| 1995 | Apr 30 |
| 1996 | May 13 |
| 1997 | May 18 |
| 1998 | Apr 28 |
| 1999 | Apr 25 |
| 2000 | Apr 30 |
| 2001 | Apr 29 |
| 2002 | May 20 |
| 2003 | Apr 27 |
| 2004 | May 4 |
| 2005 | May 12 |
| 2006 | May 7 |
| 2007 | Apr 19 |
| 2008 | May 1 |
| 2009 | May 18 |
| 2010 | May 10 |
| 2011 | Apr 30 |
| 2012 | Apr 30 |
| 2013 | May 14 |
| 2014 | Apr 27 |
| 2015 | May 23 |
| 2016 | May 16 |
| 2017 | May 9 |
| 2018 | Apr 30 |
| 2020 | May 14 |
| 2021 | May 11 |
| 2022 | Apr 30 |
| 2023 | May 18 |
| 2024 | Apr 26 |
| 2025 | May 1 |
| 2026 | May 12 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1940 | 138 |
| 1941 | 122 |
| 1943 | 126 |
| 1944 | 162 |
| 1945 | 141 |
| 1946 | 152 |
| 1947 | 137 |
| 1948 | 146 |
| 1950 | 159 |
| 1952 | 146 |
| 1953 | 131 |
| 1954 | 131 |
| 1955 | 196 |
| 1957 | 115 |
| 1958 | 127 |
| 1959 | 122 |
| 1960 | 151 |
| 1961 | 130 |
| 1962 | 156 |
| 1963 | 109 |
| 1964 | 101 |
| 1965 | 119 |
| 1966 | 119 |
| 1967 | 122 |
| 1968 | 150 |
| 1969 | 150 |
| 1970 | 141 |
| 1972 | 119 |
| 1973 | 120 |
| 1974 | 137 |
| 1975 | 157 |
| 1976 | 155 |
| 1977 | 157 |
| 1978 | 157 |
| 1979 | 136 |
| 1980 | 139 |
| 1981 | 139 |
| 1982 | 170 |
| 1983 | 144 |
| 1984 | 144 |
| 1985 | 161 |
| 1986 | 158 |
| 1987 | 155 |
| 1988 | 146 |
| 1989 | 151 |
| 1990 | 161 |
| 1991 | 150 |
| 1992 | 140 |
| 1993 | 116 |
| 1994 | 142 |
| 1995 | 169 |
| 1996 | 143 |
| 1997 | 136 |
| 1998 | 184 |
| 1999 | 161 |
| 2000 | 150 |
| 2001 | 149 |
| 2002 | 146 |
| 2003 | 157 |
| 2004 | 151 |
| 2005 | 160 |
| 2006 | 157 |
| 2007 | 192 |
| 2008 | 170 |
| 2009 | 145 |
| 2010 | 164 |
| 2011 | 175 |
| 2012 | 160 |
| 2013 | 162 |
| 2014 | 167 |
| 2015 | 146 |
| 2016 | 146 |
| 2017 | 160 |
| 2018 | 166 |
| 2020 | 155 |
| 2021 | 164 |
| 2022 | 155 |
| 2023 | 157 |
| 2024 | 171 |
| 2025 | 160 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1940 | 13.4 °C |
| 1941 | 14.9 °C |
| 1943 | 13.1 °C |
| 1944 | 14.9 °C |
| 1945 | 13.7 °C |
| 1946 | 13.8 °C |
| 1947 | 14.2 °C |
| 1948 | 15.0 °C |
| 1949 | 15.5 °C |
| 1950 | 13.0 °C |
| 1952 | 15.2 °C |
| 1953 | 15.0 °C |
| 1954 | 14.1 °C |
| 1955 | 16.4 °C |
| 1957 | 13.9 °C |
| 1958 | 13.8 °C |
| 1959 | 15.6 °C |
| 1960 | 14.1 °C |
| 1961 | 14.0 °C |
| 1962 | 14.2 °C |
| 1963 | 13.4 °C |
| 1964 | 13.6 °C |
| 1965 | 12.7 °C |
| 1966 | 13.2 °C |
| 1967 | 13.1 °C |
| 1968 | 14.0 °C |
| 1969 | 14.3 °C |
| 1970 | 14.4 °C |
| 1972 | 13.8 °C |
| 1973 | 14.9 °C |
| 1974 | 13.8 °C |
| 1975 | 14.2 °C |
| 1976 | 13.9 °C |
| 1977 | 14.8 °C |
| 1978 | 14.2 °C |
| 1979 | 14.0 °C |
| 1980 | 14.6 °C |
| 1981 | 14.5 °C |
| 1982 | 14.1 °C |
| 1983 | 14.8 °C |
| 1984 | 14.3 °C |
| 1985 | 14.8 °C |
| 1986 | 14.8 °C |
| 1987 | 16.0 °C |
| 1988 | 15.5 °C |
| 1989 | 14.8 °C |
| 1990 | 14.8 °C |
| 1991 | 16.2 °C |
| 1992 | 13.2 °C |
| 1993 | 14.0 °C |
| 1994 | 14.2 °C |
| 1995 | 14.5 °C |
| 1996 | 14.1 °C |
| 1997 | 13.6 °C |
| 1998 | 16.4 °C |
| 1999 | 16.1 °C |
| 2000 | 14.5 °C |
| 2001 | 15.4 °C |
| 2002 | 15.5 °C |
| 2003 | 14.6 °C |
| 2004 | 14.7 °C |
| 2005 | 16.2 °C |
| 2006 | 15.6 °C |
| 2007 | 15.7 °C |
| 2008 | 15.2 °C |
| 2009 | 14.5 °C |
| 2010 | 16.4 °C |
| 2011 | 15.7 °C |
| 2012 | 16.2 °C |
| 2013 | 15.2 °C |
| 2014 | 14.7 °C |
| 2015 | 15.9 °C |
| 2016 | 16.2 °C |
| 2017 | 15.4 °C |
| 2018 | 16.1 °C |
| 2020 | 15.1 °C |
| 2021 | 15.9 °C |
| 2022 | 15.6 °C |
| 2023 | 15.4 °C |
| 2024 | 16.5 °C |
| 2025 | 15.5 °C |
| 2026 | 15.0 °C |
What this means for you: Since 1940, Acton's last spring frost has come about 1 day 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 Fergus Shand Dam (NOAA GHCN-Daily, from Environment and Climate Change Canada). Years with too many missing days are left out.