You can argue about the reasons behind climate change, but it’s hard to argue with facts. Indiana state climatologist Beth Hall presented facts when addressing the Indiana certified crop advisers.
“Indiana is getting warmer, and Indiana is getting wetter,” Hall says. “We have data to back that up going into the late 1800s.”
She draws data from the Indiana Climate Change Impacts Assessment. It was prepared by the Purdue University Climate Change Research Center. Melissa Widhalm is operations manager of PCCRC. She brought the same message to soil and water conservation district supervisors at the Indiana Association of Soil and Water Conservation Districts annual meeting.
Farmers should know about these trends so they can develop plans to continue to grow crops successfully, Widhalm says. One way to help offset expected changes to some degree is to improve soil health, she notes. Growing cover crops when cash crops aren’t in the field can help improve soils over the long term.
Here is a closer look at changes in Indiana’s climate over the past 125 years. Both Hall and Widhalm provided this information, which is documented in the ICCIA report.
Indiana is warmer. From 1895 to 2016, Indiana’s average temperature increased 0.1 degree F per decade. Indiana is about 1.2 degrees warmer on average today than in 1895.
Rate of warming increased midcentury. From 1895 through the 1950s, average temperature increase was right at 0.1 degree warmer per decade. The maximum temperature didn’t increase at all, and the minimum rose 0.2 degree per decade. From 1960 through 2016, the average increase was 0.4 degree per decade, with the average max temp rising 0.3 degree and the average minimum temp up 0.5 degree.
Extremes happen more frequently. Four of Indiana’s hottest years since 1900 occurred after 2005. Only one of the 10 coldest years occurred in that same period. 2014 tied with 1958 for the seventh coldest year in Indiana. The other most recent year in the top 10 coldest was 1979.
Here’s where extreme shifts come in. The 2012 season is the hottest on record since 1900, yet 2014 tied for seventh coldest, and both 2016 and 2017 were back in the top 10 warmest years.
Indiana is wetter. From 1895 through 1959, average annual precipitation increased 0.32 inch per decade. From 1960 forward, the increase is 1.33 inches per decade — a fourfold increase in rate, Widhalm notes.
Amount of annual increase varies by region. Average annual rainfall is anywhere from 3.3 to 6.7 inches per year higher today compared to 1895. Here is the annual increase in inches since 1895 by crop reporting districts: northwest, 5.6; north-central, 4.8; northeast, 3.3; west-central 6.5; central, 5.7, east-central 3.7; southwest, 6.2; south-central 6.9; southeast, 6.7.
Since 1895, spring and summer have increased more rapidly in seasonal rainfall than fall and winter.
Growing season is longer. Based on an increased average number of days between the last 32-degree-F day in the spring and the first 32-degree-F day in the fall, the growing season averaged nine days longer for the period of 1991 through 2012 versus 1901 through 1960, Hall reports. That’s according to data published by the National Oceanic and Atmospheric Administration. Growing seasons across the entire country were longer, varying from six to 19 days longer.