Official National Weather Service observations at Chicago O'Hare recorded a maximum temperature of 83°F on August 30, 2026, exceeding the 1991–2020 normal of 81°F by 2°F and confirming the 82–83°F outcome. This measurement, taken at 12:25 PM local time under partly cloudy skies with light winds and scattered showers, aligned closely with regional model guidance and surface analyses from NOAA. The market's 100% consensus reflects traders' confidence in these verified station data, which serve as the authoritative source for resolution. Minor challenges could arise only from an atypical switch to an alternate station reading or post-hoc quality-control revisions, both of which remain highly improbable given the clear observational record.