Traders see the 88–91°F range as most probable for Seattle’s August 5 maximum because ensemble guidance places the city near the western edge of a modest upper-level ridge, with limited offshore flow and marine-layer moderation keeping temperatures from climbing higher. Recent model runs from the National Weather Service show daytime highs building into the upper 80s under mostly sunny skies, consistent with the broader warmer-than-normal summer outlook from NOAA and the Climate Prediction Center. Key variables differentiating the leading bins include subtle differences in low-level wind direction and subsidence strength; stronger onshore flow or increased afternoon cloud cover could cap readings near 88–89°F, while clearer conditions and slight easterly flow support 90–91°F. Historical early-August averages near 76–79°F underscore the current anomaly, though short-range model updates through tonight remain the next catalyst likely to refine probabilities.