ZIP 94304 Zone 9b

California · USDA zone 9b, average annual extreme minimum 25°F to 30°F.

Nearest qualified station: PALO ALTO, CA US (USC00046646), 3.5 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is February 1. Median first 32°F is December 7. The 50% growing-season length is 310 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 28Earlier date. A last 32°F on or after this day is common.
50%February 1Median.
10%March 4Later 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%November 20Earlier date. A first 32°F on or before this day is uncommon.
50%December 7Median.
90%January 6Later 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%347
50%310
90%272

28°F threshold

10%50%90%
Last, on or afterFebruary 17January 4December 15
First, on or beforeDecember 3December 22January 25
Season at least365 days358 days318 days

36°F threshold

10%50%90%
Last, on or afterApril 15March 11February 5
First, on or beforeNovember 3November 21December 8
Season at least292 days252 days214 days

Station PALO ALTO, CA US (USC00046646). Completeness flag R, 18 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 95.8%. 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 · California cities