**Forecasts for Seattle's August 31, 2026, daily maximum temperature center on the low-to-mid 70s°F, driving the tightest market probabilities on the 74–75°F (25.0%) and 76–77°F (23.5%) bins.** Multiple models and agency outlooks issued near August 29 project highs ranging from the upper 60s to mid-70s, with several converging near 70–74°F under mostly sunny to partly cloudy conditions after earlier showers. Key differentiating factors include the strength and timing of post-frontal clearing, northerly flow off the cooler marine layer from Puget Sound and the Pacific, and the degree of solar heating under variable cloud cover. Recent days featured showers and lower maxima (mid-to-upper 60s), setting up modest recovery as high pressure influences the region. Historical climatology shows an average high of ~74.5°F for the date, providing a baseline that current guidance largely follows without strong anomalous warming or cooling signals. Model spread and subtle differences in boundary-layer moisture or wind speed explain why probabilities remain closely split rather than concentrated on a single outcome, with lower-probability tails reflecting scenarios of greater marine influence or fuller sunshine. New National Weather Service and numerical model updates over the next 48 hours will likely refine the exact maximum before resolution.