ZIP 45501 Zone 6a

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

Nearest qualified station: SPRINGFIELD WTP, OH US (USC00337935), 3.3 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 25. Median first 32°F is October 19. The 50% growing-season length is 175 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 25Median.
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 4Earlier date. A first 32°F on or before this day is uncommon.
50%October 19Median.
90%November 1Later 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%194
50%175
90%151

28°F threshold

10%50%90%
Last, on or afterApril 30April 15March 31
First, on or beforeOctober 16October 30November 10
Season at least214 days197 days177 days

36°F threshold

10%50%90%
Last, on or afterMay 20May 5April 22
First, on or beforeSeptember 23October 6October 20
Season at least172 days153 days133 days

Station SPRINGFIELD WTP, OH US (USC00337935). 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 289.9 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Ohio cities