How many chill hours does 91403 get?

91403 averages 321 chill hours per winter, ranging from 151 to 592 across the last 10 years.

What hardiness zone is 91403?

91403 is in USDA hardiness zone 10a.

Location almanac

The short answer

91403 averages 321 chill hours per winter (151–592 across 10 years) in USDA zone 10a.

91403 climate
Average chill hours	321 (151–592 across 10 winters)
USDA hardiness zone	10a

Computed from 10 winters of ERA5 hourly temperature (Open-Meteo, 2015–2025); zones from USDA PHZM 2023. Data updated July 3, 2026. See methodology.

Every variety in our database, checked against 91403’s chill hours and zone:

Chill and zone requirements are comfortably met in 91403.

Show 12 more good fit varieties

Possible in a good year or a favorable microclimate — click through for the caveats.

How many chill hours does 91403 get?: 91403 averages 321 chill hours per winter, ranging from 151 to 592 across the last 10 years.
What hardiness zone is 91403?: 91403 is in USDA hardiness zone 10a.

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[1] Open-Meteo / Copernicus ERA5. Historical Weather API (hourly 2m temperature) — accessed July 2026
[2] USDA / PRISM (Oregon State University). 2023 USDA Plant Hardiness Zone Map — accessed July 2026