ZIP 91913 Zone 10b

California · USDA zone 10b, average annual extreme minimum 35°F to 40°F.

Nearest qualified station: SAN DIEGO BROWN FLD, CA US (USW00003178), 3.5 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is January 6. Median first 32°F is December 31. The 50% growing-season length is 365 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%December 13Earlier date. A last 32°F on or after this day is common.
50%January 6Median.
10%February 5Later 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%December 11Earlier date. A first 32°F on or before this day is uncommon.
50%December 31Median.
90%January 30Later 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%365
50%365
90%345

36°F threshold

10%50%90%
Last, on or afterMarch 7February 2December 29
First, on or beforeDecember 1December 20January 25
Season at least361 days326 days284 days

Station SAN DIEGO BROWN FLD, CA US (USW00003178). Completeness flag R, 23 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 25.1%. Freeze dates are conditional on that threshold occurring. Elevation 157 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · California cities