ZIP 53186 Zone 5b

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

Nearest qualified station: BROOKFIELD WWTP, WI US (USC00471062), 2.5 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 30. Median first 32°F is October 14. The 50% growing-season length is 164 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 16Earlier date. A last 32°F on or after this day is common.
50%April 30Median.
10%May 15Later 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%September 28Earlier date. A first 32°F on or before this day is uncommon.
50%October 14Median.
90%October 27Later 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%184
50%164
90%144

28°F threshold

10%50%90%
Last, on or afterMay 3April 19April 5
First, on or beforeOctober 10October 25November 7
Season at least209 days188 days167 days

36°F threshold

10%50%90%
Last, on or afterMay 29May 10April 28
First, on or beforeSeptember 21October 3October 17
Season at least162 days142 days121 days

Station BROOKFIELD WWTP, WI US (USC00471062). Completeness flag R, 13 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 253 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