Last frost date in Hillsborough, NJ

Average last frost
April 30

The average last frost in Hillsborough is April 30. By May 14 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about October 20, which leaves 172 frost-free days. An early freeze before October 5 happens one year in ten.

Safe after (10% risk)
May 14
Average first frost
Oct 20
Frost-free season
172 days
Hard freeze (28°F) ends
Apr 15
Next 7 nights in Hillsborough

Frost likely Fri night, low 32°F

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

  1. ThuOct 2238°
  2. FriOct 2332°frost
  3. SatOct 2433°possible frost
  4. SunOct 2536°possible frost
  5. MonOct 2643°
  6. TueOct 2743°
  7. WedOct 2843°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 30First frost Oct 20172 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND172 frost-free days
Frost risk through the year at Somerville 4 NW, 7.4 miles from Hillsborough.

Planting calendar for Hillsborough

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

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesMay 7–May 21
PumpkinsMay 14–May 28
SunflowersApr 30–May 21
CucumbersMay 14–May 21
CornMay 7–May 21
Sweet potatoesMay 21–Jun 4
WatermelonMay 14–May 28
Green beansMay 7–May 28
ZucchiniMay 7–May 21
OkraMay 21–Jun 4
PeppersMay 14–May 28
BasilMay 7–May 21
Butternut squashMay 7–May 21
CantaloupeMay 14–May 28
EggplantMay 14–May 28
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesApr 2–Apr 16
OnionsMar 19–Apr 9
CarrotsApr 9–May 14
LettuceApr 16–May 7
BroccoliApr 2–Apr 16
BeetsApr 2–May 14
PeasMar 19–Apr 2
CabbageApr 2–Apr 16
RadishesMar 26–May 7
Brussels sproutsApr 16–Apr 30
SpinachMar 19–Apr 9
CilantroApr 16–May 7
KaleApr 2–Apr 16
Collard greensApr 2–Apr 16
TurnipsApr 2–Apr 16
DillApr 30–May 14
CeleryMay 7–May 14
CauliflowerApr 16–Apr 30
LeeksApr 16–Apr 30
Swiss chardApr 16–May 14
ParsleyApr 16–May 7
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 6–Nov 10
GarlicSep 29–Nov 3
Daffodil bulbsSep 22–Nov 3
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesApr 2–Apr 16
AsparagusApr 2–Apr 16

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 15Apr 30May 14Oct 5Oct 20Nov 3
Hard freeze, 28°FApr 1Apr 15May 1Oct 15Oct 31Nov 12

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 Somerville 4 NW (USC00288194) sits 7.4 miles from the center of Hillsborough at 134 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 Hillsborough, NJ?

The average last frost date in Hillsborough is April 30, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 14.

When is the first frost in Hillsborough?

The first frost in fall usually comes around October 20. One year in ten it arrives before October 5.

How long is the growing season in Hillsborough?

About 172 days between the average last and first frost.

When should I plant tomatoes in Hillsborough?

Plant tomato seedlings outside from May 7 to May 21. Start seeds indoors six to eight weeks earlier.

Nearby in New Jersey

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