The good news is there are equal chances for a wetter than normal and a drier than normal August. More good news is that there are equal chances for a warmer than normal and cooler than normal August.
The bad news is forecasters aren't prepared to say any more than that. Their actual 30-day forecast for August calls for "normal" rainfall and "normal" temperatures.
Define normal however you like. A week of 90-degree highs and a week of 70-degree highs averages out to 80 degrees for the two weeks. But you certainly won't feel like it's normal on any one day.
The actual "normals" are based on comparisons to the 30-year period covering 1981-2010, notes Ken Scheeringa, Indiana assistant state climatologist. The only area of Indiana that could be slightly warmer than normal in August is extreme southeast Indiana, according to predictions. It may be brushed by a large mass of warmer than normal air predicted to cover much of the southern U.S. in August. Cooler than normal temperatures in the northern plain states should stay well north and west of Indiana.
There is a nearly 4.5 degree difference in maximum daily temperature in August from northwest Indiana to southwest Indiana, with the southwest crop reporting district being warmer. Likewise, daily minimum temperatures in August are about 4.0 degrees higher in southwest Indiana compared to northeast Indiana.
Average rainfall over the 30-year reference period is highest in north-central Indiana, at 3.88 inches, and lowest in southwest and south-central Indiana, at 3.17 and 3.18 inches, respectively.
The temperature gradient from northern Indiana to southern Indiana is not surprising since Indiana is a long, narrow state, with the northern counties sometimes behaving more like Michigan in terms of weather, and the southern counties lining up more with Kentucky. Chrisney in Spencer County is 30 miles south of Louisville, Ky.
Michigan expects normal temperature and rainfall patterns in August as well. However, Kentucky could be warmer than normal except in extreme western counties, and expects normal precipitation totals statewide.