My forecast for later this Fall and Winter is generally warmer than normal. So it may be odd to suggest this could be the last weekend with temperatures over 25°C. The caveat to my long-range forecast is that first, we have to get through October.
All indications are that the end of September and much of October could be cool and damp. Once that trend is over we should see the impacts from a growing El Nino that will bring us a much warmer start to winter than seen in the last several years. This weekend is likely to be the ending of a warmer than normal stretch as cool air rushes into the region next week.
We will see a mix of sun and cloud on Friday with daytime highs near 26°C, but the humidity will make it feel more like 31°C. There will likely be more clouds early in the day and more sun later this afternoon.
Saturday will be partly cloudy with temperatures climbing to near 26°C in the afternoon. There is the slight risk of an isolated thunderstorm in the afternoon and early evening.
The warmer than normal temperatures continue into Sunday under partly cloudy skies and daytime highs near 27°C.
Next week we see a change in the overall weather pattern across North America that will eventually bring widespread rain and much colder temperatures.