A clear and calm night will send temperatures plummeting throughout the Midwest into the Ohio Valley, producing the season's first frost, and in rural area, the first deep freeze.

The WeatherRadar shows the sky clearing and calm winds developing. This combination will allow the temperatures to drop quickly after sunset tonight and temperatures will drop into the low 30s, with rural locations likely seeing temperatures in the upper 20s.

The TemperatureRadar shows the coldest spots tonight with the frosty temperatures reaching into the southern Appalachians and parts of the Mid-Atlantic on Saturday morning, as below-normal temperatures linger across the East this weekend.

The freeze will damage summer plants and likely end the growing season. Sensitive plants that can't be moved inside can be covered by plastic.