Frost Dates for Altadena, CA

Based on data from Pasadena weather station, 3 miles away

Elevation: 1358 ft

Frost Dates

Last Spring Frost (50%) A 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide. January 8
First Fall Frost (50%) A 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. January 7

This location has a nearly year-round growing season with a brief frost risk period in winter.

30% Probability

Only a 30% chance of frost remaining by this date. Use these dates for a safer planting window, especially for tender plants sensitive to cold.
Last Spring Frost January 14
First Fall Frost January 1
34.19°N, 118.13°W © OpenStreetMap

Growing Season

365 Days January 8 to January 7

USDA Hardiness Zone

Hardiness zones indicate which perennial plants can survive winter in your area. For annual vegetables, frost dates and growing season length matter more than hardiness zone.
Zone 10b

Avg. annual minimum: 35 to 40°F

Learn more

Köppen Climate

The Köppen climate classification system categorizes climates based on temperature and precipitation patterns.
Csa Hot-Summer Mediterranean

Hot, dry summers and mild, wet winters. Classic Mediterranean climate ideal for grapes, olives, tomatoes, and herbs. Summer irrigation is usually necessary.

Köppen climate map

Temperature

Avg High Avg Temp Avg Low
Temperature table
Average monthly temperatures (°F)
Month Avg High Avg Temp Avg Low
January68°57°46°
February69°58°46°
March73°61°48°
April76°63°51°
May78°66°54°
June84°71°58°
July89°76°62°
August91°77°63°
September90°76°62°
October83°70°56°
November75°62°50°
December67°56°45°

Precipitation

Precipitation table
Average monthly precipitation (inches)
MonthPrecipitation
January10.3
February8.0
March5.7
April3.0
May0.0
June0.0
July0.0
August0.0
September0.0
October0.0
November3.1
December7.5

Sunrise / Sunset

Daylight Pacific Time (PT) Longest: 14h 17m · Shortest: 9h 43m
Sunrise and sunset table
Sunrise, sunset, and daylight on the 15th of each month (Pacific Time (PT))
Month Sunrise Sunset Daylight
January7:03 AM5:01 PM9h 58m
February6:44 AM5:30 PM10h 46m
March7:10 AM6:55 PM11h 45m
April6:27 AM7:19 PM12h 52m
May5:55 AM7:42 PM13h 47m
June5:45 AM8:01 PM14h 16m
July5:56 AM8:00 PM14h 04m
August6:18 AM7:35 PM13h 17m
September6:41 AM6:53 PM12h 12m
October7:04 AM6:11 PM11h 07m
November6:32 AM4:43 PM10h 11m
December6:56 AM4:40 PM9h 44m

Nearby Stations

San Gabriel Fire Dept, CA January 4 - January 2 Mt Wilson Cbs, CA April 28 - November 15 Los Angeles Dwtn Usc Campus, CA Burbank Valley Pump Plt, CA January 2 - December 26 Burbank Glendale Pasadena AP, CA December 31 - December 28 U C L A, CA

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