Official observations from Environment Canada stations, including Toronto Pearson and City Centre, recorded a daily maximum of 25°C on September 10, 2026, under mainly sunny skies with west-northwest winds gusting to 35–45 km/h and minimal cloud cover. This aligned closely with pre-event model consensus from GFS and Environment Canada guidance projecting highs of 23–26°C amid near-seasonal September conditions, with afternoon peaks driven by strong solar insolation and light mixing. Trader consensus at 100% implied probability for 25°C reflects verification against these authoritative surface measurements rather than forecasts. Only an anomalous station discrepancy or post-analysis revision would realistically alter the outcome, though such adjustments remain rare for daily temperature records.