Last frost date in New London, CT

Average last frost
April 16

The average last frost in New London is April 16. By April 30 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about October 28, which leaves 194 frost-free days. An early freeze before October 13 happens one year in ten.

Safe after (10% risk)
Apr 30
Average first frost
Oct 28
Frost-free season
194 days
Hard freeze (28°F) ends
Apr 3
Next 7 nights in New London

No frost in the next 7 nights

National Weather Service forecast, updated Oct 22, 12:57 UTC

  1. ThuOct 2243°
  2. FriOct 2339°
  3. SatOct 2439°
  4. SunOct 2541°
  5. MonOct 2646°
  6. TueOct 2744°
  7. WedOct 2845°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 16First frost Oct 28194 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND194 frost-free days
Frost risk through the year at Groton NEW London Airport, 2.5 miles from New London.

Planting calendar for New London

Windows count forward or back from the average frost dates above. Click a crop for dates across Connecticut.

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesApr 23–May 7
PumpkinsApr 30–May 14
SunflowersApr 16–May 7
CucumbersApr 30–May 7
CornApr 23–May 7
Sweet potatoesMay 7–May 21
WatermelonApr 30–May 14
Green beansApr 23–May 14
ZucchiniApr 23–May 7
OkraMay 7–May 21
PeppersApr 30–May 14
BasilApr 23–May 7
Butternut squashApr 23–May 7
CantaloupeApr 30–May 14
EggplantApr 30–May 14
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 19–Apr 2
OnionsMar 5–Mar 26
CarrotsMar 26–Apr 30
LettuceApr 2–Apr 23
BroccoliMar 19–Apr 2
BeetsMar 19–Apr 30
PeasMar 5–Mar 19
CabbageMar 19–Apr 2
RadishesMar 12–Apr 23
Brussels sproutsApr 2–Apr 16
SpinachMar 5–Mar 26
CilantroApr 2–Apr 23
KaleMar 19–Apr 2
Collard greensMar 19–Apr 2
TurnipsMar 19–Apr 2
DillApr 16–Apr 30
CeleryApr 23–Apr 30
CauliflowerApr 2–Apr 16
LeeksApr 2–Apr 16
Swiss chardApr 2–Apr 30
ParsleyApr 2–Apr 23
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 14–Nov 18
GarlicOct 7–Nov 11
Daffodil bulbsSep 30–Nov 11
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 19–Apr 2
AsparagusMar 19–Apr 2

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 3Apr 16Apr 30Oct 13Oct 28Nov 12
Hard freeze, 28°FMar 19Apr 3Apr 17Oct 25Nov 9Nov 27

Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.

Where these numbers come from

NOAA station Groton NEW London Airport (USW00014707) sits 2.5 miles from the center of New London at 10 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.

Questions

When is the last frost in New London, CT?

The average last frost date in New London is April 16, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 30.

When is the first frost in New London?

The first frost in fall usually comes around October 28. One year in ten it arrives before October 13.

How long is the growing season in New London?

About 194 days between the average last and first frost.

When should I plant tomatoes in New London?

Plant tomato seedlings outside from April 23 to May 7. Start seeds indoors six to eight weeks earlier.

Nearby in Connecticut

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