Trader consensus on Polymarket tightly clusters around 56-59°F for Seattle-Tacoma International Airport's highest temperature on April 8, mirroring National Weather Service guidance forecasting partly cloudy skies with highs near 57°F and long-range models like GFS and ECMWF ensembles averaging in the upper 50s. This balance reflects persistent spring marine layer effects—low stratus clouds and cool onshore flow from the Pacific—that often limit peak heating in the Puget Sound region, despite NOAA's above-average April temperature outlook for the Pacific Northwest driven by a developing upper-level ridge. Historical April averages hover at 57°F, but day-to-day variability from cloud timing and solar insolation creates the narrow spread; watch for overnight model runs and NWS updates through April 7 for potential shifts.