**Trader sentiment for Toronto’s lowest temperature on August 21, 2026, clusters tightly around 12–16 °C because official forecasts and model guidance converge on an overnight minimum in that narrow band.** Environment Canada and major outlets project clear or mostly clear skies with a low near 16–18 °C at Pearson International Airport (the likely resolution station), while some ensemble members and localized cooling scenarios allow brief dips toward 14–15 °C. Clear, calm conditions enable efficient radiative cooling after sunset, but moderate humidity and dew points in the mid-teens limit how far temperatures can fall before reaching saturation. Light southerly or variable winds reduce mixing yet prevent extreme drops, keeping the floor above 12 °C in most guidance. The near-even probabilities across 12 °C, 13 °C, 14 °C, and 15 °C reflect small but meaningful differences in timing of the minimum, exact station microclimate, and any late-evening cloud intrusions or wind shifts. Outcomes below 11 °C or above 17 °C carry negligible implied odds because they fall well outside current model consensus and historical late-August climatology for the region. Upcoming hourly observations and the final midnight-to-midnight minimum will decide resolution, with any deviation from clear-sky assumptions able to shift the outcome within the tightly bunched central range.