Over the last several years, I have noticed an interesting phenomenon as I travel throughout the city: Skyscrapers create their own micro climates. Traveling south on Lake Shore Drive toward the John Hancock Center, I sometimes see fog drifting in that pretty much obscures the skyline, only to discover clear skies once I cross North Avenue heading south on LaSalle. The phenomenon is real: The combination of building heat radiation and height, the proximity of buildings to each other, and Lake Michigan all effect how water vapor in the air reaches its dew point, thereby creating fog. The buildings act like gigantic funnels, which is why the fog moves about, slip sliding away and then returning.
I knew I would see fog at some point during the day. At 10AM I was headed to a meeting in the Loop. It was quite warm and sunny, but a cold front was scheduled to move in later in the day. Later in the day turned out to be 11:00PM. When I passed through the building doors to the street, the sky had turned white and there was a chill in the air. I had my trusty Abercrombie & Fitch hoodie, so I was covered both literally and figuratively.
At first, I thought my photographic plans were ruined, but then I saw the fog dancing between the buildings. Some portions of the sky were thick white, while other portions had a mosaic of white and light blue. I stood in Maggie Daley Park for this photograph. The Willis (Sears) Tower went in and out of the fog, so I had to be patient.
Below is a photograph of the CNA Building. Enjoy the lettering. CNA sold the building back in March 2016 for $108 million. It will be moving its headquarters to 151 North Franklin next summer.
Click on the photograph to enlarge it.