Flights to and from O'Hare International Airport resumed last night after they were halted because of the fog, and more than an inch of rain fell there, setting a record for Feb. 20.
Then it was the wind that kicked up, prompting high wind warnings.
An official National Weather Service high wind warning was replaced late Thursday by a wind advisory, which lasts until 3 p.m. today.
The warnings said gusts could reach 45 mph.
Also remaining today are flood warnings near rivers, including the east branch of the DuPage River at Bolingbrook.
Among the National Weather Service's various flood warnings, the one for the DuPage River says it could reach flood stage early this morning and continue to rise.
It said the river had reached 19.1 feet as of 7:50 last night, with flood stage at 19.5 feet. The river is expected to peak at 19.7 feet.
Yet the weather service considers the flooding minor and expects the river to drop back down during the night.
DuPage County's stormwater management officials said Thursday they expected "a minor operation" of the county's flood control facilities early Thursday afternoon.
In a written statement, DuPage officials said parts of the Chicago region "have experienced heavier rainfall totals with a more significant threat for river flooding" than DuPage.
Still, a combination of rain and melting snow has the potential to trigger a minor operation of flood control facilities along Salt Creek and the West Branch of the DuPage River, officials said. Peak river elevations were expected late Thursday night.
The most likely form of localized flooding in DuPage will be caused by clogged or frozen inlets, officials said.
Earlier Thursday, wind gusts expected to be up to 60 miles per hour blew away a dense fog that hampered the evening rush hour.
A dense fog advisory expired at 7 p.m. As of 6:15 p.m., flights were beginning to arrive and depart after a temporary ground stop due to poor visibility, according to the Chicago Aviation Department. More than 500 flights had been canceled between the two airports.
As of 6:43 p.m., the National Weather Service reported that 1.01 inches of rain had fallen at O'Hare International Airport. WBBM Newsradio reported that it was a record for Feb. 20.
A rain and snow mix this morning shifted over to all rain later, causing heavy snow melt flooding streets and rivers.
Rainfall creates heavy snow melt, and because the ground is frozen, the water has nowhere to go, which causes some streets to flood.
The National Weather Service Advanced Hydraulic Prediction Service said the Des Plaines and Fox Rivers were not in danger of flooding during the day Thursday, but it warned the melting snow could quickly reverse that.
Puddles began to form on area roads as rain fell Thursday, especially in curbside lanes next to snow piles.
In Naperville, Loomis Street was closed Thursday afternoon at the Burlington Northern Santa Fe Railroad crossing because of flooding. City officials were encouraging drivers to cross the tracks at Columbia Street or the underpass at Washington Street instead.