ZIP 53227 Zone 5b

Wisconsin · USDA zone 5b, average annual extreme minimum -15°F to -10°F.

Nearest qualified station: WEST ALLIS, WI US (USC00479046), 2.5 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 26. Median first 32°F is October 22. The 50% growing-season length is 177 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.

ProbabilityDateHow to read it
90%April 12Earlier date. A last 32°F on or after this day is common.
50%April 26Median.
10%May 12Later 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.

ProbabilityDateHow to read it
10%October 7Earlier date. A first 32°F on or before this day is uncommon.
50%October 22Median.
90%November 3Later 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 longDays
10%197
50%177
90%158

28°F threshold

10%50%90%
Last, on or afterApril 30April 14April 1
First, on or beforeOctober 19November 1November 14
Season at least219 days200 days178 days

36°F threshold

10%50%90%
Last, on or afterMay 23May 8April 23
First, on or beforeSeptember 29October 10October 24
Season at least176 days156 days137 days

Station WEST ALLIS, WI US (USC00479046). Completeness flag R, 11 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 220.4 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Wisconsin cities