Trader sentiment reflects forecast uncertainty for Seattle's August 5 high, with market-implied odds clustered around 84–89°F as National Weather Service models show modest spread in peak readings. A building high-pressure ridge and limited marine layer influence from the Pacific are supporting daytime warming into the mid to upper 80s, while ensemble guidance highlights sensitivity to exact timing of any afternoon clearing. The leading 86–87°F outcome at 37% captures the central tendency of recent runs, yet 28.5% odds on 84–85°F underscore lingering model disagreement on boundary-layer mixing. Official updates from NOAA later today will likely narrow resolution criteria around observed maximums.