**Current forecasts from NOAA and AccuWeather indicate a minimum temperature near 59–60°F for Seattle on August 21, 2026, aligning with the market’s heavy weighting on the 60–61°F bin at 67% implied probability.** Typical late-August marine air influence and light winds under partly cloudy skies prevent significant radiational cooling, keeping overnight lows close to seasonal norms of 57–59°F. Recent model consensus shows no strong cold-air advection or clear-sky radiative cooling that would drop readings into the mid-50s, while the absence of marine-layer stratus or onshore flow supports the slight upward bias toward 60°F. Traders appear to be pricing in the official National Weather Service forecast for Sea-Tac Airport, the likely resolution source, with only marginal probability assigned to outliers that would require an unusual nocturnal temperature drop or measurement anomaly.