Over a hundred of flights have been canceled at airports in Chicago as light rain and dense fog continue to push through northern Illinois and northwest Indiana.

As of 8:25 p.m., 101 flights had been canceled at Midway International Airport and 49 flights had been canceled at O’Hare International Airport, according to the Chicago Department of Aviation. Both airports are also seeing some minor delays.

The cancellations and delays are related to the foggy conditions, according to Gregg Cunningham, spokesman for the department of aviation. Travelers flying through Midway on Monday night or Tuesday should confirm their flight status with their airline.

The National Weather Service issued a dense fog advisory Sunday morning for much of the Chicago area. Widespread fog, which could cause visibilities to drop to a quarter-mile or less, began affecting the area after 7 p.m.

The advisory will remain in effect until 3 a.m. Monday in Cook, Lake, Will, De Kalb, Kane, DuPage, Kendall and Grundy counties, the weather service said. Winnebago, Boone, McHenry and Lake counties will remain under the advisory until 6 a.m. Monday.

Drivers should use caution while traveling on foggy roadways and “be prepared to encounter rapidly changing visibility,” the weather service said.

Light rain is expected to continue Sunday evening before heavier rain showers and thunderstorms move into the area after 10 p.m. alongside cooler temperatures that are expected to dip below 40 degrees, the weather service said.

On Monday, showers and thunderstorms are expected to continue hitting the area after 9 a.m., the weather service said. Temperatures are expected to reach into the 50s before dropping nearly 20 degrees in the nighttime hours, making way for snowy conditions on Tuesday.