Recent National Weather Service guidance and ensemble model runs point to a high in the mid-70s for Chicago on August 3, driven by persistent northerly flow behind recent showers that has suppressed temperatures well below the 83.8°F climatological normal. Limited afternoon mixing and possible partial clearing introduce modest uncertainty around peak readings, keeping the 78–79°F and 80–81°F bins closely matched as traders weigh guidance spreads. Historical analogs from similar post-frontal setups in early August show highs rarely exceeding 82°F under these conditions, reinforcing the market’s tight clustering around the upper 70s while highlighting sensitivity to any last-minute model shifts before resolution.