Official National Weather Service observations from Austin-area stations recorded a daily maximum of 90-91°F on October 9, 2026, under clear skies and light northeasterly winds that permitted strong solar heating without significant cloud cover or mixing. This outcome aligns with above-normal conditions for early October, when the 1991-2020 average high sits near 85°F, and matches real-time surface data showing afternoon peaks in that narrow band. Market-implied odds reached 100% because verified measurements left little room for alternative thresholds. Revisions to preliminary reports or use of a non-standard station could theoretically alter resolution, though such changes remain rare once final climatological summaries are issued.