ZIP 49519 Zone 6a

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

Nearest qualified station: GRAND RAPIDS, MI US (USW00094860), 8.8 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 29. Median first 32°F is October 20. 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 14Earlier date. A last 32°F on or after this day is common.
50%April 29Median.
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%October 4Earlier date. A first 32°F on or before this day is uncommon.
50%October 20Median.
90%November 2Later 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%195
50%174
90%151

28°F threshold

10%50%90%
Last, on or afterMay 2April 16April 2
First, on or beforeOctober 19November 2November 17
Season at least220 days200 days178 days

36°F threshold

10%50%90%
Last, on or afterMay 23May 7April 24
First, on or beforeSeptember 26October 7October 20
Season at least171 days152 days132 days

Station GRAND RAPIDS, MI US (USW00094860). Completeness flag S, 29 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 237.1 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Michigan cities