Last frost date in Danbury, CT

Average last frost
May 1

In Danbury, the last spring frost comes around May 1 in an average year. Wait until May 16 if you want 90% odds of no more frost. The first fall frost usually arrives about October 14, which leaves 166 frost-free days. An early freeze before October 1 happens one year in ten.

Safe after (10% risk)
May 16
Average first frost
Oct 14
Frost-free season
166 days
Hard freeze (28°F) ends
Apr 18
Next 7 nights in Danbury

Frost possible in low spots Thu night, low 36°F

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

  1. ThuOct 2236°possible frost
  2. FriOct 2333°possible frost
  3. SatOct 2433°possible frost
  4. SunOct 2537°
  5. MonOct 2643°
  6. TueOct 2740°
  7. WedOct 2842°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost May 1First frost Oct 14166 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND166 frost-free days
Frost risk through the year at Danbury Municipal Airport, 1.9 miles from Danbury.

Planting calendar for Danbury

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
TomatoesMay 8–May 22
PumpkinsMay 15–May 29
SunflowersMay 1–May 22
CucumbersMay 15–May 22
CornMay 8–May 22
Sweet potatoesMay 22–Jun 5
WatermelonMay 15–May 29
Green beansMay 8–May 29
ZucchiniMay 8–May 22
OkraMay 22–Jun 5
PeppersMay 15–May 29
BasilMay 8–May 22
Butternut squashMay 8–May 22
CantaloupeMay 15–May 29
EggplantMay 15–May 29
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesApr 3–Apr 17
OnionsMar 20–Apr 10
CarrotsApr 10–May 15
LettuceApr 17–May 8
BroccoliApr 3–Apr 17
BeetsApr 3–May 15
PeasMar 20–Apr 3
CabbageApr 3–Apr 17
RadishesMar 27–May 8
Brussels sproutsApr 17–May 1
SpinachMar 20–Apr 10
CilantroApr 17–May 8
KaleApr 3–Apr 17
Collard greensApr 3–Apr 17
TurnipsApr 3–Apr 17
DillMay 1–May 15
CeleryMay 8–May 15
CauliflowerApr 17–May 1
LeeksApr 17–May 1
Swiss chardApr 17–May 15
ParsleyApr 17–May 8
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsSep 30–Nov 4
GarlicSep 23–Oct 28
Daffodil bulbsSep 16–Oct 28
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesApr 3–Apr 17
AsparagusApr 3–Apr 17

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 18May 1May 16Oct 1Oct 14Oct 29
Hard freeze, 28°FApr 3Apr 18May 4Oct 11Oct 27Nov 8

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 Danbury Municipal Airport (USW00054734) sits 1.9 miles from the center of Danbury at 457 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 Danbury, CT?

The average last frost date in Danbury is May 1, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 16.

When is the first frost in Danbury?

The first frost in fall usually comes around October 14. One year in ten it arrives before October 1.

How long is the growing season in Danbury?

About 166 days between the average last and first frost.

When should I plant tomatoes in Danbury?

Plant tomato seedlings outside from May 8 to May 22. Start seeds indoors six to eight weeks earlier.

Nearby in Connecticut

All 25 cities in Connecticut