Off subject and I don't know what made me look it up, but Chicago has not had a single daily record low temperature from 2020-present. But from 2020-present, there have been 30 daily record highs, including ties. Note that this does not include record high minimum temps, but just record high temps. Every month except July and September has seen at least one record high, but there were none between June 18-August 22... essentially "primetime summer." It could be that Chicago is being affected by the Midwest summer warming hole that has gotten more attention in recent years, which describes the observed summer cooling/lack of warming in the Midwest as a result of land use changes, in particular more extensive crop growth. This could be acting to at least temper the max temp potential in Chicago during the heart of summer, as Chicago summers have not necessarily averaged cool during that timeframe.
But going back to the original statement, 30 record highs compared to no record lows is quite lopsided. I think it's some combination of the macro trends overall and also UHI, which has gotten worse and worse around O'Hare. There will be another record low at some point... just don't know when it will be.
Subsurface right now has +2.1 OHC, which is 2nd all time to this point in the year, only below 1997. The all time OHC for all times of the year is +2.56, and again we are already at +2.1
CPC has the 26c isotherm down on the thermocline.. deep sea fish that are used to 65F are swimming in 80F water right now.