Recent forecasts indicate a cooler northeasterly air mass will limit Toronto's September 28 maximum to the low 20s Celsius, with widespread cloud cover and light drizzle potential suppressing daytime heating. Model consensus from Environment Canada and other agencies shows afternoon peaks clustered between 19–21°C under overcast skies and moderate northeast winds, consistent with the market's tight spread favoring 20–21°C outcomes. Seasonal lake moderation from Lake Ontario and reduced solar insolation in late September further constrain the upper end, though brief clearing could push readings toward 22°C. Traders weigh these variables against historical late-September averages near 19°C, with fresh model runs and observational updates expected to refine probabilities ahead of resolution.