Trader consensus on Polymarket reflects tight clustering around 68-75°F for Chicago's highest temperature on April 16, driven by the latest National Weather Service (NWS) guidance and ensemble forecasts from GFS and ECMWF models showing highs in the upper 60s to mid-70s amid a building upper-level ridge ushering warmer air from the south. This above-normal outlook (April 16 climatological average: 59°F per NOAA) follows a recent warming trend after early-April chillier conditions, with NOAA's spring 2026 predictions for warmer-than-average temperatures in the Midwest adding context. Differentiating factors include variable cloud cover from lingering moisture—potentially capping highs at 68-71°F if persistent, or allowing 72-75°F under sunnier breaks—and light southerly winds (10-15 mph) enhancing mixing. New model runs expected overnight and morning soundings will refine uncertainty before resolution at Chicago O'Hare.