Current ensemble forecasts from Environment Canada and global models indicate overnight lows near 9–11°C for Toronto on October 4, shaped by southerly flow, moderating high pressure, and limited radiative cooling under partly cloudy skies. Model spread remains notable at this lead time, with variations in cloud cover, wind mixing, and any weak frontal moisture determining whether temperatures dip sharply or stay elevated. Historical October averages place the typical minimum around 10°C, providing context for why traders see nearly equal implied odds between sub-6°C and 16°C+ outcomes. Updated model runs and Environment Canada briefings over the next 48 hours will likely narrow the range.