The driving under the influence conviction was the fifth in 19 years for Malcolm C. Fox Jr., 43, who listed an address in the 100 block of Hamilton.
Judge Richard Klaus on Thursday called Fox a "danger to the public" at the sentencing.
Fox pleaded guilty in January to driving on May 23 in Rantoul at a time when his blood alcohol level was 0.08 percent or greater. No one was injured.
Fox testified he was a substitute teacher for the Urbana school district who loved his job, but has known for a long time that he has a problem with substance abuse. He also testified he was recently diagnosed as suffering from bipolar disorder.
Klaus noted that Fox had sought inpatient treatment four different times and reported to a court services officer that in 2010, before his latest arrest, he was drinking a case of beer every other day.