When to plant in New London, CT
Planting dates worked out from New London'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 11
about a 50% chance of a later one
Average first fall frost
Oct 27
1 year in 10 by Oct 11
Frost-free days
199
median, 1991–2020
Station used: Groton · 5.2 km away · station 12 m, town 17 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 8 – Mar 22 | May 3 – May 17 | Jun 27 |
| Sweet pepper | Feb 22 – Mar 8 | May 3 – May 17 | Jul 2 |
| Lettuce (leaf) | Feb 22 – Mar 1 | Mar 29 – Apr 12 | May 8 |
| Peas | — | Mar 29 – Apr 26 | May 23 |
| Bush beans | — | Apr 26 – May 17 | Jun 15 |
| Carrot | — | Apr 9 – May 21 | Jun 8 |
| Beet | — | Apr 9 – May 21 | May 29 |
| Potato | — | Apr 9 – Apr 30 | Jun 18 |
| Kale | Feb 22 – Mar 8 | Apr 5 – Apr 19 | May 18 |
| Broccoli | Feb 15 – Mar 1 | Mar 29 – Apr 19 | May 28 |
| Cucumber | Apr 5 – Apr 12 | May 3 – May 17 | Jun 22 |
| Summer squash and zucchini | Apr 5 – Apr 12 | May 3 – May 17 | Jun 17 |
| Winter squash | Apr 5 – Apr 12 | May 3 – May 17 | Jul 22 |
| Sweet corn | — | Apr 26 – May 17 | Jun 25 |
| Onion (from sets) | — | Mar 29 – Apr 19 | Jun 27 |
| Garlic | — | Oct 13 – Nov 10 (fall) | following summer |
| Spinach | — | Mar 29 – Apr 26 | May 6 |
| Basil | Mar 22 – Apr 5 | May 3 – May 17 | Jun 29 |
New London'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 |
|---|---|
| 1958 | Apr 14 |
| 1959 | Apr 23 |
| 1960 | Apr 20 |
| 1961 | May 3 |
| 1962 | Apr 21 |
| 1963 | Apr 29 |
| 1964 | May 4 |
| 1965 | Apr 21 |
| 1966 | May 11 |
| 1967 | May 7 |
| 1968 | Apr 12 |
| 1969 | Apr 21 |
| 1970 | May 7 |
| 1971 | Apr 25 |
| 1972 | Apr 28 |
| 1973 | Apr 21 |
| 1974 | May 8 |
| 1975 | Apr 23 |
| 1976 | Apr 13 |
| 1977 | Apr 11 |
| 1978 | Apr 24 |
| 1979 | Apr 22 |
| 1980 | Apr 18 |
| 1981 | Apr 22 |
| 1982 | Apr 23 |
| 1983 | Apr 2 |
| 1984 | Apr 22 |
| 1985 | Apr 12 |
| 1986 | Apr 13 |
| 1987 | Apr 2 |
| 1988 | Apr 23 |
| 1990 | Apr 19 |
| 1991 | Apr 19 |
| 1993 | Apr 8 |
| 1994 | Apr 9 |
| 1995 | Apr 17 |
| 1996 | Apr 12 |
| 1997 | Apr 15 |
| 1998 | Apr 12 |
| 1999 | Apr 11 |
| 2000 | Apr 15 |
| 2002 | Apr 7 |
| 2003 | Apr 18 |
| 2004 | Apr 6 |
| 2007 | Apr 11 |
| 2008 | Apr 3 |
| 2011 | Apr 8 |
| 2015 | Apr 6 |
| 2016 | Apr 10 |
| 2017 | Mar 30 |
| 2020 | Apr 23 |
| 2021 | Apr 4 |
| 2023 | Apr 3 |
| 2024 | Mar 24 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1958 | 174 |
| 1959 | 175 |
| 1960 | 183 |
| 1961 | 165 |
| 1962 | 186 |
| 1963 | 147 |
| 1964 | 160 |
| 1965 | 166 |
| 1966 | 168 |
| 1967 | 175 |
| 1968 | 201 |
| 1969 | 184 |
| 1970 | 165 |
| 1971 | 194 |
| 1972 | 164 |
| 1973 | 179 |
| 1974 | 149 |
| 1975 | 190 |
| 1976 | 180 |
| 1977 | 195 |
| 1978 | 167 |
| 1979 | 170 |
| 1980 | 174 |
| 1981 | 171 |
| 1982 | 177 |
| 1983 | 201 |
| 1984 | 166 |
| 1985 | 199 |
| 1986 | 180 |
| 1987 | 206 |
| 1990 | 191 |
| 1991 | 184 |
| 1993 | 185 |
| 1994 | 216 |
| 1995 | 201 |
| 1996 | 203 |
| 1997 | 190 |
| 1999 | 186 |
| 2000 | 167 |
| 2002 | 199 |
| 2003 | 189 |
| 2004 | 211 |
| 2008 | 203 |
| 2011 | 205 |
| 2015 | 195 |
| 2017 | 223 |
| 2023 | 212 |
| 2024 | 224 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1958 | 15.7 °C |
| 1959 | 17.3 °C |
| 1960 | 16.6 °C |
| 1961 | 16.9 °C |
| 1962 | 15.9 °C |
| 1963 | 16.1 °C |
| 1964 | 16.3 °C |
| 1965 | 16.8 °C |
| 1966 | 16.2 °C |
| 1967 | 15.7 °C |
| 1968 | 17.0 °C |
| 1969 | 17.1 °C |
| 1970 | 16.9 °C |
| 1971 | 16.8 °C |
| 1972 | 16.0 °C |
| 1973 | 17.0 °C |
| 1974 | 16.9 °C |
| 1975 | 16.7 °C |
| 1976 | 17.1 °C |
| 1977 | 17.2 °C |
| 1978 | 16.2 °C |
| 1979 | 17.6 °C |
| 1980 | 17.8 °C |
| 1981 | 17.4 °C |
| 1982 | 17.0 °C |
| 1983 | 17.8 °C |
| 1984 | 17.3 °C |
| 1985 | 17.6 °C |
| 1986 | 16.8 °C |
| 1987 | 17.2 °C |
| 1990 | 16.6 °C |
| 1991 | 18.3 °C |
| 1992 | 15.9 °C |
| 1993 | 17.4 °C |
| 1994 | 17.3 °C |
| 1995 | 16.9 °C |
| 1996 | 16.4 °C |
| 1997 | 16.3 °C |
| 1999 | 17.4 °C |
| 2000 | 16.5 °C |
| 2002 | 18.4 °C |
| 2003 | 17.6 °C |
| 2004 | 17.9 °C |
| 2007 | 18.0 °C |
| 2008 | 18.2 °C |
| 2010 | 19.5 °C |
| 2011 | 18.7 °C |
| 2017 | 18.1 °C |
| 2020 | 18.0 °C |
| 2023 | 18.4 °C |
| 2024 | 18.3 °C |
What this means for you: Since 1958, New London's last spring frost has come about 4 days earlier per decade, on average. The frost-free season has grown by about 7 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Groton (NOAA GHCN-Daily). Years with too many missing days are left out.