Lows overnight are expected to drop to sub-freezing temperatures.
National Weather Service forecasters have issued a freeze warning from 2 a.m. until 9 a.m. Friday for most of Indiana.
Temperatures could fall to as low as 29 degrees by morning.
Officials said frost and freeze conditions could kill crops and other outside vegetation and damage outdoor plumbing.
Lows should return to the mid-40s by the weekend with highs up to 60. The forecast includes a 20 percent chance of rain showers Saturday night into Sunday.