How many chill hours does 91910 get?

91910 averages 103 chill hours per winter, ranging from 48 to 232 across the last 10 years.

What hardiness zone is 91910?

91910 is in USDA hardiness zone 10b.

Location almanac

The short answer

91910 averages 103 chill hours per winter (48–232 across 10 years) in USDA zone 10b.

91910 climate
Average chill hours	103 (48–232 across 10 winters)
USDA hardiness zone	10b

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 91910’s chill hours and zone:

Chill and zone requirements are comfortably met in 91910.

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

How many chill hours does 91910 get?: 91910 averages 103 chill hours per winter, ranging from 48 to 232 across the last 10 years.
What hardiness zone is 91910?: 91910 is in USDA hardiness zone 10b.

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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