National Weather Service forecasts for Seattle on August 7 project a sunny day with highs near 85–88 °F under persistent high pressure and subsidence warming, aligning with the market’s tight clustering around the 84–87 °F bins. Marine-layer moderation from Puget Sound and the potential for a northwest sea breeze or wildfire smoke reducing insolation introduce modest uncertainty in afternoon peak readings at key stations such as KSEA. Ensemble guidance shows limited spread, yet small differences in boundary-layer mixing and exact wind timing can shift the daily maximum by 1–2 °F. With a Heat Advisory in effect, traders are pricing the balance between strong radiative heating and these localized cooling mechanisms. Updated model runs and real-time observations through the afternoon will refine the final outcome.