Pockets of dense fog could drop visibility below one half-mile on Monday night across the Chicago area, according to officials.
According to the National Weather Service, dense fog began developing Monday in parts of numerous counties, including DeKalb, Kane, DuPage, Kendall, Grundy and Will counties.
Visibility could drop quickly in those locations, with some spots featuring visibility of less than one-half mile.
In other parts of the Chicago area, including the city and the south and eastern suburbs, patchy fog will be possible throughout the evening.
NWS officials are advising motorists to use extreme caution while driving, slowing down, increasing following distance and using low-beam headlights.
Soruce : https://www.nbcchicago.com/weather/dense-fog-to-blanket-chicagos-western-suburbs-monday/2982774/