Current forecast consensus from GFS and regional models points to overnight lows of 13–15°C in Toronto on September 28 under mostly cloudy skies with light northeast winds, limiting radiative cooling. This supports trader focus on the mid-teens range while the near-even split between 8°C-or-below and 18°C-or-higher outcomes reflects uncertainty in cloud persistence and any subtle frontal timing that could shift minimums by a few degrees. Environment Canada and ECMWF guidance updates over the next 48 hours will refine boundary-layer moisture and wind fields, directly influencing whether the low settles near 14°C or edges toward warmer or cooler thresholds. Historical late-September averages near 11–12°C provide context but carry limited weight given the short-range, high-resolution model runs now dominating sentiment.