An incoming early-September Pacific storm system, with associated cloud cover, southerly flow, and widespread showers, is the main driver suppressing Seattle's high temperature on September 3 toward the mid-60s. Official National Weather Service forecasts and model consensus indicate mostly cloudy skies with rain likely in the afternoon, limiting daytime heating and holding highs near 64°F amid light to moderate precipitation. This pattern follows a cooler air mass advecting into the region, well below the early-September climatological average high near 73°F. Trader consensus reflected in the 64-65°F and 66-67°F bands captures the tight clustering around these model outputs, while lower-probability tails account for potential forecast shifts in timing or intensity of the rain. Updated NWS guidance and next model runs will refine resolution criteria tied to the daily maximum reading.