Chicago, IL – Dense fog and drizzle are creating hazardous travel conditions across northern Illinois, persisting into Thursday morning. The National Weather Service warns drivers of low visibility, especially on interstates and major roadways such as I-55 and I-90. According to the National Weather Service (NWS) Chicago office, fog is expected to intensify Wednesday night into early Thursday, with some areas experiencing near-zero visibility. Motorists are urged to slow down, use low-beam headlights, and allow extra travel time. The elevated fog risk will ease by mid-morning Thursday but will return intermittently through the weekend as warmer air and periodic rain move into the region.