Between three and five inches of snow fell in most areas. A winter storm warning remains in effect until 9 a.m. Friday. One to two more inches are expected to fall by then.
According to ABC 7 meteorologist Jerry Taft, the lake effect could dump another two to three inches on the south end of Lake Michigan. With temperatures dropping throughout the evening, wind chills will be near zero Friday morning.
Hundreds of flights were canceled at Chicago's airports, but by Thursday night the biggest travel challenges shifted to the roads.
Airlines at Midway and O'Hare reported significant cancellations and delays. At Midway, Southwest Airlines proactively canceled all flights in and out of the airport between 1 p.m. and 6 p.m. Thursday, which equates to approximately 100 flights, or 25 percent of total flights scheduled at Midway. Other airlines at Midway canceled more than 140 flights and reported minor delays.
At O'Hare, airlines canceled over 420 flights in and out of the airport. Airlines reported delays for de-icing averaging about 20 minutes.
The slick roads contributed to a number of problems for drivers. In Deerfield, five people were injured - one critically - in a multi vehicle crash. There were numerous other incidents of cars spinning out on the icy pavement.
Winter reality check sets in across the city
Before the sun came up, city snow fighters were loading up with salt. Starting around 9:30 a.m., a steady snowfall hit the city. By late Thursday evening, the Streets and Sanitation Department said more than 280 snow plows were out clearing expressways and major streets.
"Even though it's supposed to stop snowing tomorrow morning, after that the issue for us will be blowing and drifting," said Guy Tridgell, Illinois Dept. of Transportation.
"We have not touched any side streets as of yet," said said Thomas Byrne, Chicago Streets and Sanitation Commissioner. "They look pretty good though. Just they have to be patient with us in regards to getting into the side streets. We want to make sure the arterials are done and we get people home from rush hour."
That snow-fighting effort is now able to be tracked on the city's new website, ChicagoShovels.org. Officials say the site, which shows the location of snow plows, received tens of thousands of views Thursday.
"Chicago winters can change on a dime, and that's what snow command does, is actually reroute and change things, and you'll see that reflected in the map," said John Tolva, Chief Technology Officer, City of Chicago.
Earlier in the day, the snow in the Loop caught some without coats clearly off guard.
"It's a bit of a challenge with the snow blowing in your face and all, but I'm kind of glad it's coming, so we can get it out of the way," said said Rochelle Hardaway. "Hopefully, it'll end sooner. It won't drag out."
"I don't need sleeves," said Dana Green, who was out with just a vest. "I love Chicago. I love the snow. I'm great. It's a good thing right here for me."
In the neighborhoods, folks were taking shovel in hand. The wet, heavy snow had postal worker Latesha Jackson struggling to keep her letters dry.
"I'm trying, I'm trying," said Jackson. "It's pretty wet. It's kind of hard to push the cart, but it's work."
North suburban residents clear snow, have fun
In Winnetka, Tom Holmberg struggled to start his snow blower and adjust to winter.
"Not loving it that much right now, but it will come into balance once I get this snow blower started," Holmberg told ABC7.
For those without a snow blower, there was plenty of shoveling in the northern suburb.
"It's a breeze. It will take a lot more snow than this to get my heart beating pretty hard," said Tony Robinson, personal trainer.
Young hearts pumped with excitement.
"We're going to make a snowman and maybe have a snowball fight," said Charlie Kendall, Winnetka resident.
But getting around was a challenge.
"It's actually quite quicker than driving. I just go right by as everyone is backed up at stoplights," said Chris Frye.
"I promised them we would go sledding all day, and today was the day. We waited a long time," said Todd Ginsberg, Kenilworth resident.
Western suburbs deal with first snow storm of 2012
In the western suburbs, the snow started about 8:45 a.m. and fell into the evening.
At Bill Kay Chevrolet in Naperville, employees had brought the summer coupes out front due to this winter's mild temperatures.
"People usually don't come in when it snows. Usually people just browse around or their intention is to buy something. Whether or not I can earn their business today I don't know, but I sure hope I can," said ex-Marine and salesman Eric Oberlin, Bill Kay.
In Naperville, longtime residents got busy with the chores of the storm.
"It's Chicago, it happens," said resident Betty Byrne as she shoveled snow.
The city received about three inches of snow by late afternoon -- enough to keep the municipal snow command hopping. The first storm of 2012 was a chance to showcase a new computer program residents can log into to check when their streets will be cleared.
"They can look at the city in general or zoom in on to their address and see whether or not we are in their area, if it's been plowed, if it's been salted, if we're done or if it's still in progress," said Christine Schwartzhoff, operations manager, Naperville Public Works.
Schwartzhoff said being able to offer taxpayers real time information is the biggest lesson that came out of the experience with last February's blizzard.
The city's police department was grateful that it only had to deal with about 20 traffic accidents Thursday.
"If people allow themselves plenty of time, they can get there safely without being in an accident," said Sgt. Greg Bell.
Snow good news for some businesses
Plow driver Henry Meyer may have been one the few people in the Chicago area who was actually happy about the snow.
"It is nice to have nice weather, but we need the snow to make extra cash. That always helps," he told ABC7. "It is only at this time we would be out five or six times already and this is the first time, so it has hurt so far. It was bad around Christmas, because we were counting on the extra money and it never came."
While Thursday's forecast for snow and blizzard-like driving conditions may have been horrible for commuters, it was great for snow-dependent businesses that have been suffering through one of the mildest winters on record.
Veteran plow driver Jerry Gonzalez said revenue is way off because of the snow that never came.
"Lack of work and lack of income, you know, not to mention what you put out for the equipment and everything else, brand new equipment and stuff you try to get going and up and moving, and then not being able to make any money on what you put out," said Gonzalez.
With Thursday's snow, hardware stores, overstocked with unsold winter goods, have seen a renewed interest in winter. At Elston Ace Hardware, customers like Verta Ray scooped up snowblowers, ice melting products and shovels.
"Some things are in the house, but I just wanted to stock up on some more stuff just in case, you know. You know how unpredictable the weather can be," said Ray.