Recent National Weather Service and model guidance for Chicago point to an incoming cold front and associated low-pressure system driving cooler, breezy northwest flow after daytime showers on October 15, with the daily minimum most likely occurring overnight. Consensus forecasts from sources including the NHC-adjacent regional models show the low in the upper 40s under partly to mostly cloudy skies, consistent with historical October climatology near 46–47 °F yet tempered by lingering warmth from the preceding high-pressure ridge. This setup creates moderate uncertainty around exact timing of the temperature drop and any model spread in boundary-layer mixing or precipitation efficiency, supporting trader emphasis on the 68 °F+ bucket while assigning only minimal implied probability to sub-50 °F readings. Updated model runs and NWS briefings expected overnight will further refine these thresholds ahead of resolution.