Recent National Weather Service and private model guidance point to a high near 74°F for Seattle on August 23, aligning with trader emphasis on the 74–75°F bin. Late-summer marine air advection from the Pacific, combined with a weak onshore pressure gradient and possible scattered showers, is limiting daytime heating below seasonal norms. Historical climatology shows late-August highs averaging 75–77°F and declining through the month, while current ensemble runs exhibit low spread around this range. No strong offshore flow or ridge is expected to push temperatures higher, keeping the market-implied distribution centered on the low-to-mid 70s.