I really have no idea what the hell I am doing when it comes to weather forecasting. I just like to see what the majority of forecasters are saying looks "most likely". They have been suggesting a cool down towards the end of the month for some time and as we near it they are refining consistent forecasts, so it sounds like we have a reasonable shot of this coming to fruition.
A cool down in late December? You can set your calendar to it! It's called winter.
As far as next week goes, the west get cool and we might get a bit less blow torch. No cold to be found.