Latest National Weather Service model guidance positions Seattle’s May 17 high temperature near 62 °F, driven by moderate onshore flow from the Pacific and a mix of sun and high clouds that limits daytime warming. This places the 62–63 °F range as the market’s leading outcome at 39.5 % implied probability, with 64 °F or higher trailing at 26.5 % and 60–61 °F at 25.0 %. Seattle’s maritime climate typically produces mid-May highs in the upper 50s to low 60s under similar patterns, and current ensemble runs show limited spread around that central value. No major warm or cold air advection is expected before resolution, keeping lower-probability bins below 10 %. Traders will watch the final 00Z and 12Z model updates overnight for any shift in cloud cover or wind direction that could nudge the observed high across the 63–64 °F threshold.