ZIP 98499 Zone 8b

Washington · USDA zone 8b, average annual extreme minimum 15°F to 20°F.

Nearest qualified station: TACOMA #1, WA US (USC00458278), 7.1 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is March 8. Median first 32°F is November 14. The 50% growing-season length is 250 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%February 15Earlier date. A last 32°F on or after this day is common.
50%March 8Median.
10%March 31Later 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 30Earlier date. A first 32°F on or before this day is uncommon.
50%November 14Median.
90%December 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%283
50%250
90%223

28°F threshold

10%50%90%
Last, on or afterMarch 4February 11December 29
First, on or beforeNovember 8December 1January 1
Season at least338 days301 days264 days

36°F threshold

10%50%90%
Last, on or afterApril 24April 2March 13
First, on or beforeOctober 16October 31November 15
Season at least233 days209 days185 days

Station TACOMA #1, WA US (USC00458278). Completeness flag S, 26 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 7.6 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Washington cities