Frost dates / California / Cupertino

Frost dates in Cupertino, CA

The station on this page is MOFFETT FEDERAL AIRFIELD, CA US (USW00023244), 6 miles from the city point. Population in the Census 2024 estimate is 58,710.

Zone 9bUSDA average annual extreme minimum 25°F to 30°F, from ZIP 95014 (2.2 miles from the city point used on this page).

Median last 32°F is January 6. Median first 32°F is December 23. The 50% growing-season length is 353 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 16Earlier date. A last 32°F on or after this day is common.
50%January 6Median.
10%February 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%December 3Earlier date. A first 32°F on or before this day is uncommon.
50%December 23Median.
90%January 16Later 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%353
90%323

28°F threshold

10%50%90%
Last, on or afterJanuary 22January 1December 16
First, on or beforeDecember 13December 31January 22
Season at least365 days365 days362 days

36°F threshold

10%50%90%
Last, on or afterMarch 6February 6January 3
First, on or beforeNovember 20December 6December 30
Season at least340 days306 days270 days

Station MOFFETT FEDERAL AIRFIELD, CA US (USW00023244). Completeness flag R, 22 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 69.8%. Freeze dates are conditional on that threshold occurring. Elevation 11.9 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Planting calendar for Cupertino · Zone 9b

Check a crop against this station

Cupertino, CA

Zone 9bAverage annual extreme minimum 25°F to 30°F

Median last 32°F is January 6. Median first 32°F is December 23. The 50% growing-season length is 353 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%

California. Nearest qualified station: MOFFETT FEDERAL AIRFIELD, CA US (USW00023244), 6 miles. Median last 32°F January 6. Median first 32°F December 23. The 50% growing-season length is 353 days.

Open the ZIP page · Crop guides for California

32°F probabilities at this station
10%50%90%
Last 32°F on or afterFebruary 4January 6December 16
First 32°F on or beforeDecember 3December 23January 16

Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

A wall calendar surrounded by vegetables, herbs, seed packets, and watering cans.

Planting calendar

Windows below are from UC ANR, UC Master Gardener Program, Time of planting, retrieved 2026-10-10. North and North Coast = Monterey County north; South Coast = San Luis Obispo County south; Interior Valleys = Sacramento, San Joaquin, and similar valleys; Desert Valleys = Imperial and Coachella Valleys. Source line on the page: California Master Gardener Handbook, Table 13.2, Adapted from Vegetable Gardening Illustrated 1994.

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