Official observations from Environment Canada stations, including Toronto Pearson International Airport, recorded a daily maximum of 24°C on September 9, 2026, aligning precisely with the market's 100% consensus. This outcome reflects verified thermometer data under partly cloudy, breezy conditions with light precipitation, consistent with regional model guidance and near the September climatological average high of roughly 23°C. Trader certainty stems from the final post-event data release, which leaves minimal room for adjustment. Only an improbable late revision to the official record or a redefinition of the measurement window could alter the result.