Last frost date in Belvidere, IL

Average last frost
April 24

Expect the last frost in Belvidere around April 24. Frost after May 8 happens in only one year out of ten. The first fall frost usually arrives about October 17, which leaves 174 frost-free days. An early freeze before October 2 happens one year in ten.

Safe after (10% risk)
May 8
Average first frost
Oct 17
Frost-free season
174 days
Hard freeze (28°F) ends
Apr 13
Next 7 nights in Belvidere

No frost in the next 7 nights

Later than usual: the average first frost here is October 17.

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

  1. ThuOct 2247°
  2. FriOct 2348°
  3. SatOct 2450°
  4. SunOct 2549°
  5. MonOct 2645°
  6. TueOct 2741°
  7. WedOct 2843°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 24First frost Oct 17174 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND174 frost-free days
Frost risk through the year at Rockford Gtr Rockford Airport, 11.6 miles from Belvidere.

Planting calendar for Belvidere

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

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesMay 1–May 15
PumpkinsMay 8–May 22
SunflowersApr 24–May 15
CucumbersMay 8–May 15
CornMay 1–May 15
Sweet potatoesMay 15–May 29
WatermelonMay 8–May 22
Green beansMay 1–May 22
ZucchiniMay 1–May 15
OkraMay 15–May 29
PeppersMay 8–May 22
BasilMay 1–May 15
Butternut squashMay 1–May 15
CantaloupeMay 8–May 22
EggplantMay 8–May 22
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 27–Apr 10
OnionsMar 13–Apr 3
CarrotsApr 3–May 8
LettuceApr 10–May 1
BroccoliMar 27–Apr 10
BeetsMar 27–May 8
PeasMar 13–Mar 27
CabbageMar 27–Apr 10
RadishesMar 20–May 1
Brussels sproutsApr 10–Apr 24
SpinachMar 13–Apr 3
CilantroApr 10–May 1
KaleMar 27–Apr 10
Collard greensMar 27–Apr 10
TurnipsMar 27–Apr 10
DillApr 24–May 8
CeleryMay 1–May 8
CauliflowerApr 10–Apr 24
LeeksApr 10–Apr 24
Swiss chardApr 10–May 8
ParsleyApr 10–May 1
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 3–Nov 7
GarlicSep 26–Oct 31
Daffodil bulbsSep 19–Oct 31
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 27–Apr 10
AsparagusMar 27–Apr 10

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 10Apr 24May 8Oct 2Oct 17Oct 30
Hard freeze, 28°FMar 31Apr 13Apr 27Oct 14Oct 28Nov 10

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 Rockford Gtr Rockford Airport (USW00094822) sits 11.6 miles from the center of Belvidere at 730 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 Belvidere, IL?

The average last frost date in Belvidere is April 24, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 8.

When is the first frost in Belvidere?

The first frost in fall usually comes around October 17. One year in ten it arrives before October 2.

How long is the growing season in Belvidere?

About 174 days between the average last and first frost.

When should I plant tomatoes in Belvidere?

Plant tomato seedlings outside from May 1 to May 15. Start seeds indoors six to eight weeks earlier.

Nearby in Illinois

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