Official observations from the National Weather Service at Chicago O’Hare confirmed a daily maximum of 86–87°F on October 12, 2026, shattering the prior record of 84°F set in 2008 and aligning precisely with the market’s 100% implied probability for that outcome. Unseasonably strong southerly flow, abundant sunshine, and minimal cloud cover enabled rapid daytime heating well above the 1991–2020 normal of 65°F, consistent with National Weather Service forecasts that had anticipated near-record warmth. This skin-in-the-game consensus among traders reflects the definitive post-event data release, leaving negligible probability for adjacent bins. Only a substantial revision to the official climatological report could alter the resolution.