ZIP 60085 Zone 6a

Illinois · USDA zone 6a, average annual extreme minimum -10°F to -5°F.

Nearest qualified station: WAUKEGAN, IL US (USC00119029), 1.2 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 30. Median first 32°F is October 19. The 50% growing-season length is 170 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 15Earlier date. A last 32°F on or after this day is common.
50%April 30Median.
10%May 14Later 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 30Earlier date. A first 32°F on or before this day is uncommon.
50%October 19Median.
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%190
50%170
90%150

28°F threshold

10%50%90%
Last, on or afterMay 3April 20April 5
First, on or beforeOctober 12October 30November 13
Season at least213 days191 days170 days

36°F threshold

10%50%90%
Last, on or afterMay 27May 8April 25
First, on or beforeSeptember 22October 8October 24
Season at least170 days151 days128 days

Station WAUKEGAN, IL US (USC00119029). Completeness flag R, 12 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 213.4 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Illinois cities