Napa County, California · Frost dates
Napa County frost dates.
First-frost, last-frost, and growing-season length for Napa County, California. Sourced from NOAA 1991-2020 Climate Normals.
Data confidence: high · USDA zone: 9b
32°F — light freeze
Last spring frost
- 10%
- 04-30
- 20%
- 04-23
- 50%
- 04-07
- 80%
- 03-09
- 90%
- 02-23
First fall frost
- 10%
- 11-14
- 20%
- 11-21
- 50%
- 12-05
- 80%
- 12-21
- 90%
- 01-01
28°F — killing freeze
Last spring freeze
- 10%
- 04-09
- 20%
- 03-30
- 50%
- 02-18
- 80%
- 01-04
- 90%
- 12-23
First fall freeze
- 10%
- 11-29
- 20%
- 12-06
- 50%
- 12-30
- 80%
- 02-04
- 90%
- 03-04
Growing season length (days, 28°F threshold)
- Short year
- 234
- Median
- 315
- Long year
- 436
Source NOAA station
ANGWIN PACIFIC UNION COLLEGE, CA US
7.7 mi · 30 yrs of record (1991–2020) · 1715 ft elev.
Data from ANGWIN PACIFIC UNION COLLEGE, CA US, 7.7 miles away with 30-year NOAA record (1991-2020).
Bield Farm earns its predictions.
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