Last frost date in Green Bay, WI
Expect the last frost in Green Bay around May 7. Frost after May 22 happens in only one year out of ten. The first fall frost usually arrives about October 9, which leaves 154 frost-free days. An early freeze before September 23 happens one year in ten.
- Safe after (10% risk)
- May 22
- Average first frost
- Oct 9
- Frost-free season
- 154 days
- Hard freeze (28°F) ends
- Apr 27
No frost in the next 7 nights
Later than usual: the average first frost here is October 9.
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2248°
- FriOct 2352°
- SatOct 2455°
- SunOct 2547°
- MonOct 2642°
- TueOct 2741°
- WedOct 2842°
Planting calendar for Green Bay
Windows count forward or back from the average frost dates above. Click a crop for dates across Wisconsin.
TomatoesMay 14–May 28
PumpkinsMay 21–Jun 4
SunflowersMay 7–May 28
CucumbersMay 21–May 28
CornMay 14–May 28
Sweet potatoesMay 28–Jun 11
WatermelonMay 21–Jun 4
Green beansMay 14–Jun 4
ZucchiniMay 14–May 28
OkraMay 28–Jun 11
PeppersMay 21–Jun 4
BasilMay 14–May 28
Butternut squashMay 14–May 28
CantaloupeMay 21–Jun 4
EggplantMay 21–Jun 4
PotatoesApr 9–Apr 23
OnionsMar 26–Apr 16
CarrotsApr 16–May 21
LettuceApr 23–May 14
BroccoliApr 9–Apr 23
BeetsApr 9–May 21
PeasMar 26–Apr 9
CabbageApr 9–Apr 23
RadishesApr 2–May 14
Brussels sproutsApr 23–May 7
SpinachMar 26–Apr 16
CilantroApr 23–May 14
KaleApr 9–Apr 23
Collard greensApr 9–Apr 23
TurnipsApr 9–Apr 23
DillMay 7–May 21
CeleryMay 14–May 21
CauliflowerApr 23–May 7
LeeksApr 23–May 7
Swiss chardApr 23–May 21
ParsleyApr 23–May 14
Tulip bulbsSep 25–Oct 30
GarlicSep 18–Oct 23
Daffodil bulbsSep 11–Oct 23
StrawberriesApr 9–Apr 23
AsparagusApr 9–Apr 23Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Apr 24 | May 7 | May 22 | Sep 23 | Oct 9 | Oct 25 |
| Hard freeze, 28°F | Apr 10 | Apr 27 | May 12 | Oct 5 | Oct 25 | Nov 7 |
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 Green Bay Botanical (USC00473271) sits 5.6 miles from the center of Green Bay at 694 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 Green Bay, WI?
The average last frost date in Green Bay is May 7, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 22.
When is the first frost in Green Bay?
The first frost in fall usually comes around October 9. One year in ten it arrives before September 23.
How long is the growing season in Green Bay?
About 154 days between the average last and first frost.
When should I plant tomatoes in Green Bay?
Plant tomato seedlings outside from May 14 to May 28. Start seeds indoors six to eight weeks earlier.
Nearby in Wisconsin
- HowardMay 7
- De PereApr 30
- AppletonMay 4
- ManitowocApr 30
- NeenahMay 4
- OshkoshApr 24
- SheboyganApr 25
- Fond du LacApr 27
- West BendMay 1
- Stevens PointMay 4
- WausauMay 6
- GermantownMay 6