Recent forecasts from sources including the National Weather Service point to an overnight low near 50°F in Seattle on September 30 as clearing skies follow Tuesday’s rain, allowing moderate radiational cooling under light northerly winds. Model consensus and historical September climatology support a minimum in the upper 40s to low 50s, with minimal precipitation risk and highs in the low-to-mid 60s. Trader positioning around the 50-51°F bin reflects this guidance, while the notable probability on 45°F or below captures potential for stronger cooling if winds remain calm longer than expected. New model runs and official updates overnight will refine the exact threshold ahead of market resolution.