Current National Weather Service and model guidance for Chicago on August 22 point to overnight lows near seasonal normals of 64–66°F, driven by clear to partly cloudy skies, light winds, and typical late-summer radiative cooling after daytime highs around 80–82°F. Lake Michigan’s moderating influence and boundary-layer mixing further anchor minimum temperatures in this range, consistent with climatological averages. The near-even market pricing between 66–67°F and 74°F-or-higher outcomes reflects residual forecast uncertainty in cloud cover, humidity, and any subtle frontal timing that could limit nocturnal cooling or enhance mixing. Warmer scenarios would require stronger southerly flow or increased cloudiness suppressing radiational cooling, while cooler readings hinge on clearer skies and calmer conditions allowing greater heat loss. Updated model runs and NWS briefings over the next 24 hours will likely tighten this spread.