Official temperature observations from National Weather Service stations confirmed a daily high of 70-71°F in Denver on September 29, driving the market's decisive 100% implied probability for that range. This outcome aligns with verified surface measurements rather than models, reflecting cooler-than-average conditions influenced by regional air mass movement and cloud cover. September climatology typically shows highs near 75°F, but recent atmospheric patterns suppressed peak warmth. With the date concluded, resolution depends on these authoritative readings. Rare challenges could include post-analysis data corrections, though such revisions seldom alter the recorded maximum by more than a degree.