Last frost date in Los Altos, CA

Average last frost

January 6

The average last frost in Los Altos is January 6. By February 4 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about December 23, which leaves 353 frost-free days. An early freeze before December 3 happens one year in ten.

Safe after (10% risk): Feb 4
Average first frost: Dec 23
Frost-free season: 353 days
Hard freeze (28°F) ends: Jan 1

Next 6 nights in Los Altos

No frost in the next 6 nights

National Weather Service forecast, updated Oct 22, 12:57 UTC

ThuOct 2253°
FriOct 2348°
SatOct 2451°
SunOct 2552°
MonOct 2651°
TueOct 2751°

Frost risk through the year at Moffett Federal Airfield, 3.7 miles from Los Altos.

Planting calendar for Los Altos

Windows count forward or back from the average frost dates above. Click a crop for dates across California.

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost

Warm-season crops

JanFebMarAprMayJunJulAugSepOctNovDec

TomatoesFeb 15–Mar 1

PumpkinsFeb 15–Mar 1

SunflowersFeb 15–Mar 8

CucumbersFeb 22–Mar 1

CornFeb 15–Mar 1

Sweet potatoesFeb 15–Mar 1

WatermelonFeb 15–Mar 1

Green beansFeb 15–Mar 8

ZucchiniFeb 15–Mar 1

OkraFeb 15–Mar 1

PeppersFeb 15–Mar 1

BasilFeb 15–Mar 1

Butternut squashFeb 15–Mar 1

CantaloupeFeb 15–Mar 1

EggplantFeb 15–Mar 1

Cool-season crops

JanFebMarAprMayJunJulAugSepOctNovDec

PotatoesDec 9–Dec 23

OnionsNov 25–Dec 16

CarrotsDec 16–Jan 20

LettuceDec 23–Jan 13

BroccoliDec 9–Dec 23

BeetsDec 9–Jan 20

PeasNov 25–Dec 9

CabbageDec 9–Dec 23

RadishesDec 2–Jan 13

Brussels sproutsDec 23–Jan 6

SpinachNov 25–Dec 16

CilantroDec 23–Jan 13

KaleDec 9–Dec 23

Collard greensDec 9–Dec 23

TurnipsDec 9–Dec 23

DillJan 6–Jan 20

CeleryJan 13–Jan 20

CauliflowerDec 23–Jan 6

LeeksDec 23–Jan 6

Swiss chardDec 23–Jan 20

ParsleyDec 23–Jan 13

Fall bulbs and garlic

JanFebMarAprMayJunJulAugSepOctNovDec

Tulip bulbsDec 15–Jan 15

GarlicOct 15–Nov 30

Daffodil bulbsOct 15–Nov 30

Perennials

JanFebMarAprMayJunJulAugSepOctNovDec

StrawberriesDec 9–Dec 23

AsparagusDec 9–Dec 23

Frost probabilities

Threshold	Spring, 90% chance later	Spring, 50%	Spring, 10%	Fall, 10% chance earlier	Fall, 50%	Fall, 90%
Light frost, 32°F	Dec 16	Jan 6	Feb 4	Dec 3	Dec 23	Jan 16
Hard freeze, 28°F	Dec 16	Jan 1	Jan 22	Dec 13	Dec 31	Jan 22

Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.

Where these numbers come from

NOAA station Moffett Federal Airfield (USW00023244) sits 3.7 miles from the center of Los Altos at 39 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.

Questions

When is the last frost in Los Altos, CA?

The average last frost date in Los Altos is January 6, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after February 4.

When is the first frost in Los Altos?

The first frost in fall usually comes around December 23. One year in ten it arrives before December 3.

How long is the growing season in Los Altos?

About 353 days between the average last and first frost.

When should I plant tomatoes in Los Altos?

Plant tomato seedlings outside from February 15 to March 1. Start seeds indoors six to eight weeks earlier.

Nearby in California

All 348 cities in California