**Official forecasts from Environment Canada project a daytime high of 23°C for Toronto on August 28, 2026, under mainly sunny skies becoming partly cloudy, with northwest winds shifting southerly and a humidex of 25.** This aligns with the market's strong 61.5% implied probability for 23°C, reflecting trader consensus around authoritative model runs and observations. Current early-morning readings near 16°C at Pearson Airport, with clear conditions and gentle northwest flow, support gradual daytime warming without strong advection of heat. Late-August climatology typically features highs near 24–25°C, but the present synoptic pattern—cooler northerly air and limited insolation from afternoon cloud development—caps potential at the lower end of normal. Minor model spreads account for the secondary probabilities on 22°C (21.5%) and 24°C (12%), as small differences in boundary-layer mixing or wind timing can shift the peak by 1°C. No significant forecast revisions have occurred since the prior evening update, and with the day underway, resolution hinges on the official maximum recorded at primary stations. Traders appear to weigh the Environment Canada guidance heavily, consistent with its role as the authoritative source for Canadian temperature markets.