Current forecasts from the National Weather Service and major models indicate a low near 50°F for Chicago on October 5 under clear skies and light northerly winds, supporting radiational cooling but moderated by seasonal norms around 50°F. This consensus drives the near-even split between sub-40°F and 58°F+ buckets at roughly 49-50% implied probability each, as traders weigh potential model shifts or lake-effect moderation against the risk of stronger high-pressure cooling. Mid-range outcomes cluster around historical baselines, with resolution hinging on official overnight minimums at O'Hare. Updated model runs over the next 48 hours represent the key catalyst for any probability shifts.