**Recent forecasts from National Weather Service and other models point to overnight lows in the lower to mid-50s Fahrenheit for Seattle on September 3, 2026, aligning closely with the market’s top-implied outcomes around 50–55°F.** A series of low-pressure systems moving into the Pacific Northwest from the Gulf of Alaska is driving a cooler, wetter pattern that began on September 1 and continues through mid-week. These systems are producing widespread rain, south-to-southwest winds of 10–15 mph with gusts to 25 mph, and temperatures several degrees below early-September normals. Historical climatology shows an average low of 55°F for the date, with the all-time record low at 45°F, but the current synoptic setup—persistent onshore flow and cloud cover—favors suppressed nighttime radiative cooling and keeps readings in the 52–55°F range. Model consensus across short-range guidance supports this band, with limited upside potential for warmer readings unless rapid clearing occurs overnight. Traders are therefore assigning the highest implied probabilities (roughly 89% combined on 50–55°F bins) to outcomes consistent with this cooler, rainy regime, while lower-probability tails reflect the smaller chance of either stronger cooling or unexpected warming. Updated model runs and official NWS briefings in the next 24–48 hours will provide the key data points for any further shifts in these market-implied odds.