Frost Dates for Diamond Bar, CA

Based on data from Pomona/Fairplex weather station, 4 miles away

Elevation: 696 ft

Frost Dates

Last Spring Frost (50%) iA 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%) iA 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. December 28
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

30% Probability iOnly 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 26
First Fall Frost December 19
34.03°N, -117.81°W © OpenStreetMap

Growing Season

355 Days January 8 to December 28

USDA Hardiness Zone iHardiness 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 9a

Avg. annual minimum: 20 to 25°F (−7 to −4°C)

Learn more

Köppen Climate iThe 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

40° 60° 80° 100°
56°
High: 68°F
Avg: 56°F
Low: 43°F
Jan
56°
High: 67°F
Avg: 56°F
Low: 45°F
Feb
60°
High: 72°F
Avg: 60°F
Low: 47°F
Mar
63°
High: 76°F
Avg: 63°F
Low: 50°F
Apr
66°
High: 78°F
Avg: 66°F
Low: 54°F
May
71°
High: 84°F
Avg: 71°F
Low: 57°F
Jun
76°
High: 90°F
Avg: 76°F
Low: 62°F
Jul
78°
High: 92°F
Avg: 78°F
Low: 63°F
Aug
75°
High: 89°F
Avg: 75°F
Low: 60°F
Sep
67°
High: 81°F
Avg: 67°F
Low: 54°F
Oct
60°
High: 74°F
Avg: 60°F
Low: 47°F
Nov
54°
High: 67°F
Avg: 54°F
Low: 42°F
Dec
Avg High Avg Temp Avg Low

Precipitation

0" 4" 8" 12" 13.5"
13.5"
13.51"
Jan
7.4"
7.41"
Feb
9.3"
9.32"
Mar
0.3"
0.32"
Apr
0.0"
0.00"
May
0.0"
0.00"
Jun
0.0"
0.00"
Jul
0.0"
0.00"
Aug
0.0"
0.00"
Sep
0.5"
0.49"
Oct
2.3"
2.30"
Nov
10.1"
10.06"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec10h11h11.5h13h14h14.5h14h13.5h12h11h10h9.5h
Jan: 7:01 AM – 4:59 PM · 9h 58m
Feb: 6:42 AM – 5:29 PM · 10h 46m
Mar: 7:08 AM – 6:53 PM · 11h 45m
Apr: 6:26 AM – 7:17 PM · 12h 52m
May: 5:54 AM – 7:41 PM · 13h 46m
Jun: 5:43 AM – 7:59 PM · 14h 16m
Jul: 5:55 AM – 7:59 PM · 14h 04m
Aug: 6:17 AM – 7:33 PM · 13h 16m
Sep: 6:40 AM – 6:52 PM · 12h 12m
Oct: 7:02 AM – 6:10 PM · 11h 07m
Nov: 6:31 AM – 4:42 PM · 10h 11m
Dec: 6:55 AM – 4:39 PM · 9h 44m
Daylight Pacific Time (PT) Longest: 14h 17m · Shortest: 9h 44m

Nearby Stations

Ontario Intl AP, CA January 4 - December 30 Chino AP, CA January 17 - December 19 Anaheim, CA Fullerton Muni AP, CA San Gabriel Fire Dept, CA January 4 - January 2 Mt Wilson Cbs, CA April 28 - November 15

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