National Weather Service guidance and ensemble models currently favor a Seattle high near 62 °F on May 17, driven by persistent onshore flow from the cool Pacific that curbs daytime heating across the region’s maritime climate. This pattern keeps afternoon temperatures anchored in the low-to-mid 60s, consistent with mid-May climatology where highs typically range from the upper 50s to low 60s under similar synoptic conditions. The market’s heavy weighting toward the 62–63 °F and 64 °F-or-higher bins reflects trader assessment of this steady flow and limited warm-air advection, while lower ranges command minimal probability absent a sharp forecast shift. Updated model runs through the day will refine the exact peak as the onshore regime holds.