Skip to content
EveryOrchard
Menu

Location almanac

Chill hours in 98178

The short answer

98178 averages 2,345 chill hours per winter (2,1492,641 across 10 years) in USDA zone 9a.
98178 climate
Average chill hours2,345 (2,149–2,641 across 10 winters)
USDA hardiness zone9a
Last spring frosttypically March 13 – April 14
First fall frosttypically October 26 – December 5

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 98178’s chill hours and zone:

How many chill hours does 98178 get?
98178 averages 2345 chill hours per winter, ranging from 2149 to 2641 across the last 10 years.
What hardiness zone is 98178?
98178 is in USDA hardiness zone 9a.

Growing fruit trees in 98178? Get a care calendar anchored to this exact climate, with email reminders.

Start My Orchard

Sources

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