High pressure building over the Pacific Northwest has produced mostly sunny skies and light northerly winds across Seattle on October 15, 2026, supporting daytime warming into the upper 60s to low 70s according to National Weather Service point forecasts. Model consensus and observational trends favor a peak near 70–71°F, well above the 1991–2020 climatological average high of about 60°F, with minimal cloud cover and dry air limiting cooling. Official maximum temperature records from stations such as Sea-Tac will determine resolution, and any late-day marine influence or measurement variance remains the chief uncertainty. Traders have priced this range at over 50% implied probability, reflecting the current atmospheric setup and limited downside risk in the final hours.