**Trader sentiment for Seattle’s July 13 high temperature centers on official NWS guidance of a sunny 75°F under northerly flow that limits marine-layer cooling from Puget Sound.** This places the market’s top bins (78–79°F at 30.5%, 76–77°F at 23.5%, 80–81°F at 18.5%) in a tight cluster around the forecast, reflecting modest model spread on peak heating. Key drivers include persistent high pressure promoting clear skies and reduced cloud cover after earlier July variability, combined with light northerly winds that keep cooler Pacific air offshore. Seattle’s typical midsummer marine influence often caps highs near the 78°F July average, but the current pattern favors slightly warmer readings if mixing is efficient. Ensemble guidance and recent NWS Area Forecast Discussions show limited disagreement on timing or intensity, with most runs clustered in the mid-to-upper 70s and lower odds for an 80°F+ spike or sub-74°F outcome. Updated model runs and the next NWS forecast discussion remain the primary near-term catalysts that could shift probabilities within the 74–81°F range.