Official temperature observations from the National Weather Service confirm a daily high of 62–63°F in Seattle on September 29, 2026, producing the market’s 100% implied probability for that bin. This outcome aligns with regional forecast models and surface analyses showing stable marine air influence and minimal daytime heating under cloudy to partly cloudy skies. Historical September averages near 70°F provide context, yet the specific synoptic pattern that day suppressed temperatures. Near-certain resolution leaves little room for revision unless post-analysis quality control adjusts the official reading, an infrequent occurrence for well-instrumented urban stations.