Frost dates / Wisconsin / Green Bay

Frost dates in Green Bay, WI

The station on this page is GREEN BAY BOTANICAL, WI US (USC00473271), 5.6 miles from the city point. Population in the Census 2024 estimate is 106,311.

Zone 5bUSDA average annual extreme minimum -15°F to -10°F, from ZIP 54302 (1.1 miles from the city point used on this page).

Median last 32°F is May 7. Median first 32°F is October 9. The 50% growing-season length is 154 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Last 32°F in spring

NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.

Probability	Date	How to read it
90%	April 24	Earlier date. A last 32°F on or after this day is common.
50%	May 7	Median.
10%	May 22	Later date. A last 32°F on or after this day is uncommon.

First 32°F in fall

NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.

Probability	Date	How to read it
10%	September 23	Earlier date. A first 32°F on or before this day is uncommon.
50%	October 9	Median.
90%	October 25	Later date. A first 32°F on or before this day is common.

32°F growing-season length

Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.

Probability the season is at least this long	Days
10%	176
50%	154
90%	134

28°F threshold

	10%	50%	90%
Last, on or after	May 12	April 27	April 10
First, on or before	October 5	October 25	November 7
Season at least	203 days	180 days	157 days

36°F threshold

	10%	50%	90%
Last, on or after	May 31	May 19	May 4
First, on or before	September 15	September 28	October 12
Season at least	152 days	132 days	113 days

Station GREEN BAY BOTANICAL, WI US (USC00473271). Completeness flag R, 19 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 211.5 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

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Green Bay, WI

Zone 5bAverage annual extreme minimum -15°F to -10°F

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Wisconsin. Nearest qualified station: GREEN BAY BOTANICAL, WI US (USC00473271), 5.6 miles. Median last 32°F May 7. Median first 32°F October 9. The 50% growing-season length is 154 days.

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32°F probabilities at this station

	10%	50%	90%
Last 32°F on or after	May 22	May 7	April 24
First 32°F on or before	September 23	October 9	October 25

Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

A wall calendar surrounded by vegetables, herbs, seed packets, and watering cans.

Planting calendar

Frost dates for Wisconsin are above. Planting windows appear for states with a cited extension guide. The fall and seed tools use the numbers you enter and the station dates.

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