1887 through 2008 (122 Growing seasons)
Growing season is
defined as continuous temperatures > 32F,
following the last freeze
in Spring and prior to the first freeze in the Autumn.
Year 2008: Last
spring temperature < 32 F was April 28 and
Year 2008: First
Autumn temperature <32 F was October 16,
for a growing season of
170 days.
LINK: Lincoln's First Freeze Climatology, 1887-2008
122-year, 1887-2008 average growing season length: 172 days.
Standard 30-years, 1971-2000, average growing season length: 162 days.
The last 30 years,
1979-2008, average growing season length: 162 days.