Recent National Weather Service forecasts for Chicago on October 15, 2026, indicate a high near 62°F under widespread showers and thunderstorms, with the daily low expected in the mid-50s°F as cooler maritime air advects southward behind an approaching front. Persistent cloud cover and precipitation will limit daytime radiative heating while overnight radiational cooling remains modest due to high humidity and wind, keeping the minimum above typical early-October climatology of around 48°F. Model consensus from GFS and regional runs shows limited spread around these values, with any stronger cold-air push likely delayed until October 16. Traders assign the highest implied probability to 68°F or higher at 49%, reflecting uncertainty in exact minimum timing, while the 1.7% on 49°F or below aligns with the low risk of rapid clearing and enhanced cooling. Final NWS observations from O’Hare will resolve the market.