**Official forecasts from Environment Canada point to a high of 26°C on August 31 under a mix of sun and cloud with a 40% chance of showers, though model spreads and timing uncertainties have pulled trader-implied probabilities toward the 22–24°C range (combined ~78.5%).** Persistent cloud cover and periods of rain or showers limit daytime heating by reducing incoming solar radiation, while moderate easterly to southeasterly winds and high humidity further moderate peak temperatures near Lake Ontario’s moderating influence. The weekend’s warmer, more humid pattern (highs reaching 25–27°C) gives way to an unsettled regime, with precipitation likelihood and duration acting as the key variables that could suppress the daily maximum by 2–4°C depending on how long skies remain overcast. Historical late-August averages hover near 24.6°C, but the current setup favors values below that threshold. Updated model runs and official guidance over the next 48 hours will likely resolve the narrow spread among the leading outcomes by clarifying shower timing and any late-day clearing.