A wind chill advisory will be in effect for Hancock, Wood, Seneca and Wyandot counties from 4 a.m. Thursday through noon Saturday.
Wind chills Thursday are expected to range from minus-10 to minus-15.
Wind chills Thursday night and Friday night will be colder, from minus-15 to minus-24, according to the National Weather Service.
For Allen, Henry and Putnam counties, an advisory has been issued for 2 to 10 a.m. Thursday.
Wind chills are expected to range from minus-5 to minus-15.
Hardin Countys wind child advisory is from 1 a.m. Thursday to 11 a.m. Saturday.
The National Weather Service says wind chills will range from minus-10 to minus-15 Thursday morning and from minus-15 to minus-20 Friday and Saturday mornings.
These wind chills will cause frostbite in as little as 30 minutes to exposed skin, the weather service says.