ZIP 45424 Zone 6b

Ohio · USDA zone 6b, average annual extreme minimum -5°F to 0°F.

Nearest qualified station: DAYTON INTL AP, OH US (USW00093815), 7.2 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 16. Median first 32°F is October 28. The 50% growing-season length is 194 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 2Earlier date. A last 32°F on or after this day is common.
50%April 16Median.
10%May 3Later 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 16Earlier date. A first 32°F on or before this day is uncommon.
50%October 28Median.
90%November 9Later 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%213
50%194
90%175

28°F threshold

10%50%90%
Last, on or afterApril 19April 4March 21
First, on or beforeOctober 26November 6November 23
Season at least237 days215 days196 days

36°F threshold

10%50%90%
Last, on or afterMay 13April 27April 13
First, on or beforeOctober 5October 18October 30
Season at least191 days173 days153 days

Station DAYTON INTL AP, OH US (USW00093815). 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 304.8 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