Official forecasts from Environment Canada and supporting model runs indicated a nighttime low near 15°C for Toronto on September 7, driven by mild late-summer air masses, light northwest winds, and mostly clear to partly cloudy skies that limited radiative cooling. This aligned with climatological averages around 15.4°C for the date and produced the market’s near-certain 15°C outcome. Strong trader consensus reflects verified station data and minimal model spread. A realistic challenge would require an official revision from the primary reporting station due to timing of the minimum or localized urban heat effects, though such adjustments remain uncommon once preliminary observations stabilize.