Forecast models from the National Weather Service and ensemble runs indicate a stable post-frontal high-pressure regime over Chicago on August 27, with clear to partly cloudy skies, light northeast winds near 5 mph, and dew points in the upper 50s supporting radiative cooling overnight. This setup favors a minimum temperature in the mid-to-upper 60s at official stations such as O’Hare, consistent with climatological norms of 65 °F for late August. Trader consensus clusters on the 62–65 °F bins because model spreads remain modest (typically ±2–3 °F) and urban heat-island effects limit further drops, while lower-probability tails reflect residual uncertainty in boundary-layer mixing and exact timing of minimum readings. New model cycles and local observations tonight will refine resolution criteria for the daily low.