Recent National Weather Service forecasts point to a Wednesday high near 73–75°F in Chicago under mostly sunny skies, driving the market’s tight clustering around 72–75°F outcomes. This reflects cooling after Tuesday’s 86–87°F peak as a front passes and high pressure builds, limiting afternoon mixing and moisture. Model consensus supports this range, though minor differences in wind timing or cloud cover introduce uncertainty around the exact maximum. Traders weigh these official guidance shifts against historical July variability, with resolution hinging on the day’s verified peak reading. Updated NWS model runs and afternoon observations remain key near-term catalysts.