**Forecast models and official guidance from the National Weather Service point to a high near 70°F for Seattle on August 30, 2026, amid morning clouds giving way to partial afternoon clearing.** This produces market-implied odds clustered tightly around 68–71°F because multiple authoritative runs show only modest daytime warming under light southerly flow and lingering marine influence from Puget Sound. Persistent low-level stratus and higher humidity have limited solar heating so far, keeping early readings in the mid-50s to low-60s; gradual dissipation of cloud cover this afternoon allows temperatures to climb into the upper 60s or low 70s depending on the exact timing and extent of breaks. Light winds reduce mixing, so small differences in insolation or onshore advection can shift the daily maximum by a degree or two. Recent cooling after mid-August warmth (including an 88°F reading on the 25th) and scattered showers on the 29th reinforce trader caution, with consensus favoring the 70–71°F bin at 46.5% while the near-even split with 68–69°F reflects genuine uncertainty in cloud-clearing rates and model spread. Official thresholds for resolution hinge on verified observations at primary stations such as Sea-Tac, where the precise peak will determine the outcome.