We’re well into swimming season here in Chicago — but did you know we’re now entering peak swimming season?
The water is warmest in Chicago on or around Aug. 10, according to Surf Forecast, with August temps ranging from 72 to 75.5 degrees, per SeaTemperature.org.
That might seem obvious; July and August are generally the hottest months in Chicago. But lake temps lag a little behind seasonal weather shifts. The water is near its coldest at the start of March, hovering in the mid-to-high 30s.
However, the National Center for Cold Water Safety says you should treat any water under 70 degrees with caution. Meanwhile, the ideal water temperature (going by Olympic swimming regulations) is at least 77 degrees. Lake Michigan can reach that in Chicago. Sometimes.
But don’t forget: It’s often cooler by the lake …
Historic water temperature averages, with data from SeaTemperatures.org.
When Is It ‘Cooler by the Lake?’
We’re actually out of “cooler by the lake” season. That axiom is true April through June in Chicago, before the water reaches summertime highs. On warm spring days with light wind, hot air over the land rises, which allows the denser air over the lake to flow onshore. That’s your cool lake breeze!
Winds can also affect the nature of Lake Michigan swimming.
According to Tom Skilling, “When winds blow onshore, the warm surface water is pushed toward the beaches, creating ideal swimming conditions." But, the beloved meterologist explains, during the summer, "Chicago beach water temperatures can drop dramatically with brisk west winds.”
Thanks Tom!
TLDR: If you haven’t jumped in the lake yet … stop reading this newsletter and head East. You’re running out of time.
