Washington County, Iowa · Frost dates

Washington County frost dates.

First-frost, last-frost, and growing-season length for Washington County, Iowa. Sourced from NOAA 1991-2020 Climate Normals.

Data confidence: high · USDA zone: 5a

32°F — light freeze

Last spring frost

10%
05-11
20%
05-06
50%
04-28
80%
04-18
90%
04-13

First fall frost

10%
09-25
20%
10-01
50%
10-11
80%
10-19
90%
10-24

28°F — killing freeze

Last spring freeze

10%
05-02
20%
04-27
50%
04-17
80%
04-08
90%
04-03

First fall freeze

10%
10-07
20%
10-13
50%
10-22
80%
10-29
90%
11-01

Growing season length (days, 28°F threshold)

Short year
158
Median
188
Long year
212

Source NOAA station

WASHINGTON, IA US

3.4 mi · 30 yrs of record (19912020) · 687 ft elev.

Data from WASHINGTON, IA US, 3.4 miles away with 30-year NOAA record (1991-2020).

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