Temperatures are abnormally high for December in Chicago. The monthly average is 37 degrees but today could see highs in the mid-60s.

Why it matters: Unusually high temperatures are sweeping across the U.S. and could lead to more severe weather.

And when you need the real scoop on Chicago weather, we all know there is one trusted source to turn to.

• "Our observational record goes back 150 years. If we achieved the 66 degree reading, we would break a 70 year-old record," WGN-TV meteorologist Tom Skilling tells Axios. "Our winters are running four degrees warmer than they were as recently as the 1970s.
• "One in four Decembers on average has produced a 60 degree day."

The big picture: It's great to have a nice day in December, but winter warm-ups cause several problems, including severe weather.

• "The tornado system that just came through Southern Illinois and Kentucky was historic," Skilling says. "We also had a tornado touch down in Crown Point, Indiana. It was the first December tornado to ever hit the Chicago area."

Go deeper: Axios' Andrew Freedman crunched the data to show how Friday's tornadoes were powered by climate change. The research begs the question: should Chicago be worried about severe weather this week?

• "This storm out West is a giant wind machine," Skilling says. "We may see 50 to 60 mile an hour winds in Chicago tonight or tomorrow morning."

What's next: When asked about the potential for holiday snow, Skilling says, "Unless it's out there and we haven't seen it yet, the chances for snow on or before Christmas are looking a little anemic."

When it's 60s degrees in December, Chicagoans break out the cargo shorts, flip-flops and the bikes.

• So it seems like a great day to break down the city's often confusing bike signs and markings.

The breakdown: Bike advocate and Chicago Streets Blog co-editor John Greenfield shares his hierarchy of bike infrastructure in Chicago from least to most safe:

1. Sharrow: Indicates that cyclists may share the street but "don't provide dedicated space for cycling."
2. Dashed bike lanes: "Basically deluxe sharrows; drivers of wide vehicles like buses and trucks are allowed to cross into the lane if necessary." Used on streets where there’s not enough road width to install standard bike lanes.
3. Standard bike lanes: Two striped lines with bike symbols and arrows.
4. Buffered bike lanes: "Striped lines with a band of dead space to distance cyclists from moving traffic and/or car doors."
5. Plastic bollard-protected bike lanes: The flexible plastic posts are, "easily flattened by drivers."
6. Physically protected or separated bike lanes: "These use sturdy metal bollards, concrete curbs and parked cars that motorists can’t drive around."
7. Bikeway: Path separated from moving traffic, "like the Lakefront Trail or North Branch Trail."

The bottom line: Greenfield regularly pushes the city for better bike infrastructure by pointing to surveys that show that the further down the list cities go with these types of paths, the more people say they would bike.

The other side: Chicago Department of Transportation (CDOT) spokesperson Mike Claffey tells Axios that the city "installed 8.5 miles of protected lanes in 2021 and now has 35 miles total."

• He notes the city also installed nine miles of "neighborhood greenways," or sections of streets where bikes and pedestrians get priority, in 2021.
• CDOT has also recently installed contraflow lanes (where bikes go the opposite way of cars) on Wrightwood, Kilbourn and Roscoe.

The Cook County Democrats have decided which candidates they will support in 2022. (Crains Chicago Business)

🏫 CPS is sending kids home this winter break with COVID tests. (Chalkbeat Chicago)

🏙 The city is having a hard time landing a new CEO of tourism as the industry continues to reel from the pandemic. (Crain's Chicago Business)

🚔 Armed private security guards will start patrolling Bucktown this week. But the neighborhood association is mum on details. (Block Club Chicago)

🏀 Don't look now, but the DePaul men's basketball team is 9-1. (Depaulia)

After unsuccessfully trying to find lists of local businesses that give back to the community, the founders of ShoCo Chicago made their own.

How it works: Businesses apply on the ShoCo website to be part of the program, then are interviewed by co-founder Carina Daniels about their community work. They are looking to support businesses that donate to local charities or have mission-focused hiring.

• "We want to make Chicago the birthplace of the shop community movement," Daniels tells Axios.

The list: ShoCo features more than 30 businesses so far who work with disabled adults, unhoused veterans, at-risk youth or environmental programs.

• Beverage businesses include Veteran Roasters and Southside Grinds.
• Home goods producers include Meliora cleaning products and Zefiro.
• Body care products include Nico's Organics and Yasou.

Even the inflatable Frosty can't handle this weather.

📫 Send us your holiday photos and we'll publish the best ones! Just reply to this email.