Official National Weather Service observations from Atlanta Hartsfield-Jackson International Airport recorded a maximum of 89°F on September 17, 2026, placing the daily high firmly in the 88-89°F range and aligning with the market's near-certain consensus. This outcome followed forecasts from NOAA models projecting upper 80s to low 90s under clear to partly cloudy conditions, consistent with late-summer climatology for the region where average highs hover near 83°F. The strong trader positioning reflected verified preliminary climatological data (CF6 report) and minimal model spread, with only narrow uncertainty around exact peak readings or microclimate variations at secondary stations. Resolution hinged on the official airport maximum, leaving little room for revision once the report was finalized.