Recent National Weather Service and private forecast models indicate an approaching low-pressure system will bring widespread cloud cover, rain, and southerly flow to the Seattle area on September 13, limiting daytime heating and keeping highs below the 71°F seasonal average. Persistent marine influence and precipitation-driven evaporative cooling are expected to cap afternoon temperatures in the low-to-mid 60s, with model consensus centering on 64–67°F depending on exact rain timing and any brief sun breaks. This explains the tight market clustering around 62–65°F bins, where small differences in forecast precipitation rates or wind shifts could determine whether the daily maximum falls at the lower or upper end of that range. Updated model runs and local observations on the morning of the 13th will provide the final resolution data.