Official National Weather Service observations at Los Angeles International Airport recorded a maximum of 81°F on September 5, 2026, four degrees above the 1991-2020 normal of 77°F and aligning precisely with the market's dominant 80-81°F outcome. This reading, taken at 1:33 PM local time under mostly clear conditions with light westerly winds, reflects the primary resolution metric for such temperature markets and underpins the 100% implied probability. Trader consensus reflects the finalized climatological data rather than forecasts, as post-event verification eliminates model uncertainty. A shift would require redefinition of the official station or measurement protocol, scenarios with negligible historical precedent for this contract.