ZIP 60123 Zone 5b

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

Nearest qualified station: ELGIN, IL US (USC00112736), 2 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 26. Median first 32°F is October 18. The 50% growing-season length is 174 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 3Earlier date. A first 32°F on or before this day is uncommon.
50%October 18Median.
90%October 31Later 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%193
50%174
90%152

28°F threshold

10%50%90%
Last, on or afterApril 29April 14April 1
First, on or beforeOctober 15October 29November 12
Season at least216 days197 days176 days

36°F threshold

10%50%90%
Last, on or afterMay 24May 6April 22
First, on or beforeSeptember 24October 7October 21
Season at least172 days152 days132 days

Station ELGIN, IL US (USC00112736). Completeness flag S, 30 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 232.6 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