Employees are on "code blue," meaning schools offices and school system central offices will open on time.
Evening activities will not be affected, according to Harford County Public Schools Manager of Communications Jillian Lader.
The school system cited numerous road closures around the county as the reason for the delayed opening.
See the latest road closures from Harford County here.
As of 5:25 a.m., parts of the following roads were closed:
- Patterson Mill Road
- Old Robinhood Road
- Nova Scotia Road
- Knopp Road
- Harmony Church Road
- Falling Branch Road
- Craigs Corner Road
By 8 p.m. Wednesday, Harford County first responders had been called to nine water rescues, the Office of Emergency Management said.