Seattle's reputation for relentless November gloom leads most holiday fliers to assume Sea-Tac is an operational disaster waiting to happen. Bureau of Transportation Statistics data from the past three years shows the exact opposite: November is actually SEA's second-best operating month of the entire year. While crushing summer cruise traffic and peak vacation demand drag the airport down to a dismal 75.8% on-time mark in July, November flights post an impressive 85.0% on-time rate—beating the national baseline of 84.9%.
Weather perception rarely aligns with Federal Aviation Administration flow management. Pacific Northwest rain is largely steady, low-ceiling drizzle that modern instrument landing systems handle with ease. It does not spawn the towering convective thunderstorm cells that trigger rolling ground delay programs in Dallas (80.8% November on-time) or across the East Coast. Even San Francisco posts a weaker 80.0% on-time performance because its closely spaced parallel runways choke the moment routine morning stratus clouds roll through the Bay.