The first hard freeze of the season occurred overnight. The morning low bottomed out at 27F (-3C). The temperature dropped below the freezing point at 4:30am and did not rise above the freezing point until 9:30am. That's five hours of sub-freezing temperatures. Certainly, that would be considered a killing freeze. When I woke this morning, everything was coated in a thick layer of frost. There was nothing patchy about the frost this morning. Looking at the map of morning lows, you can see that the heart of the cold air was centered over the Great Lakes region.
Here are the morning lows across the area:
Home: 27F (-3C)
Indianapolis: 31 (-1C)
Cincinnati: 28 (-2C)
Coldest in Indiana: 26F (-3C) at Goshen
Coldest in the lower 48: 16F (-9C) at Grayling, MI
Coldest in Alaska: 6F (-14C)