**The market's near-certain 100% implied probability on a 72-73°F high for New York City on September 30 reflects official observational data from the National Weather Service, including Central Park station records showing a daily maximum in that narrow band.** Late-September climatology for the region typically features highs around 71°F, and the day's atmospheric conditions—stable high pressure, light southwesterly flow, and minimal cloud cover—produced a peak consistent with this outcome rather than warmer anomalies seen earlier in the month. Traders incorporated real-time surface observations and model verification, creating strong skin-in-the-game consensus. A realistic challenge would require a post-event data revision by NOAA, use of an alternative station for resolution, or an undetected measurement discrepancy exceeding normal quality-control thresholds.