**Official observations confirmed a daily high of exactly 25°C in Toronto on September 12, 2026, driving the market's near-certain pricing on that outcome.** Environment Canada forecasts and numerical weather models anticipated afternoon peaks near 24–26°C under partly cloudy skies, light southeast winds, and moderate humidity typical of early-to-mid September conditions. This aligned closely with the 1991–2020 climatological average high of 22.8°C while falling well below historical extremes above 30°C for the date. With the event concluded and consistent station readings available the following day, trader consensus reflected verified data rather than forecast uncertainty. Minor station-to-station variations or post-analysis revisions remain the only plausible paths to a different resolution threshold.