National Weather Service forecasts indicate a daytime high near 66°F for Seattle on October 1 under partly cloudy skies with light northerly winds and minimal precipitation chances, aligning closely with the market's leading 66-67°F and 68-69°F bins that together exceed 65% implied probability. This outlook reflects typical early October climatology, where average highs hover around 65°F amid transitioning fall patterns, with model consensus showing little deviation from seasonal norms due to stable high pressure and onshore flow moderating temperatures. Traders appear to weigh the narrow forecast spread against minor uncertainties in afternoon cloud cover or localized heating, while lower-probability outcomes below 64°F or above 70°F reflect limited upside from atypical warming or cooling scenarios. Updated model runs and official briefings through the day will refine these market-implied odds.