Recent atmospheric conditions over Houston kept overnight lows elevated, with a minimum of 79°F recorded at Intercontinental Airport on September 17. Persistent subtropical high pressure and southeasterly flow from the Gulf of Mexico advected warm, humid air, limiting radiational cooling under partly cloudy skies and light winds. This setup produced dew points in the mid-70s that suppressed temperature drops below the seasonal 72°F average low. Traders assigned near-even odds across the 73–79°F bins because short-term model guidance showed modest variability in boundary-layer mixing and any weak frontal passage, while higher bins reflected negligible probability given the absence of significant cold-air advection or clear-sky radiative losses. Official NWS station data will resolve the market based on the precise hourly minimum.