National Weather Service forecasts and ensemble models currently project Seattle’s May 17 high near 62 °F, driven by persistent onshore flow from the cool Pacific that moderates daytime warming across the region’s maritime climate. This pattern aligns with mid-May climatology, where average highs typically range from the upper 50s to low 60s, limiting the potential for stronger warming or sharp cooling. Trader consensus reflected in the market-implied odds—led by the 64 °F or higher outcome at 50.5 percent—captures the balance between this baseline guidance and remaining model spread that could allow modest afternoon rises. Official observations at Seattle-Tacoma International Airport will determine resolution, with any late-day shifts in wind or cloud cover able to nudge the final reading within the narrow historical envelope.