**Official National Weather Service observations from Denver International Airport recorded a maximum temperature of 87°F on October 5, 2026, at 3:21 p.m. MDT, tying the daily record last set in 2024.** This outcome aligns with a broad heat dome and downslope warming across the Front Range that drove temperatures 17°F above the 1991–2020 normal of 70°F. Clear skies, low humidity, and southwesterly flow prevented cooling, pushing readings into the upper 80s as confirmed in real-time station data and preliminary climatological summaries. Market-implied odds reached 100% for the 86–87°F bin because the observed high fell squarely within that narrow range, with minimal model or observational uncertainty remaining after the event. Only a late revision to the official record or use of an alternate station could alter resolution, though NWS reports are the standard reference for such markets.