Seattle's daily high on September 8 hinges on the interplay between Pacific marine air, the position of the thermal trough, and any inland heating under variable cloud cover, with National Weather Service models showing a narrow range centered near 72°F. Equal 25% market shares across the 68–77°F bins reflect this tight clustering of ensemble guidance and the inherent uncertainty in short-range temperature forecasts near the coast, where small shifts in onshore flow or afternoon clearing can swing the peak by several degrees. Historical early-September climatology places the normal high near 75°F, providing context for why traders see limited probability outside the central outcomes absent a stronger high-pressure ridge or unusual marine intrusion. Updated model runs and local observations over the next 48 hours will likely refine these odds.