Latest National Weather Service guidance and ensemble models indicate a Tuesday high near 77°F in Seattle under zonal flow aloft and strengthening onshore marine flow, which favors near-normal temperatures with morning clouds limiting peak heating. The tight clustering between 78–79°F and 80–81°F outcomes reflects model sensitivity to exact marine-layer depth, boundary-layer moisture, and afternoon clearing timing, with some private forecasts edging slightly warmer. Seasonal normals hover near 77–79°F, and the absence of strong offshore ridging or heat-dome patterns keeps extreme outliers improbable while sustaining uncertainty between the upper 70s and low 80s ahead of final model runs.