After a reprieve from very intense heat, the next round is on its way.

For Adelaide, hot days and uncomfortably hot nights are on the cards from Friday, with residents and holiday-makers having to wait at least four days until a cool change arrives on Monday 30th.

In Melbourne and Hobart, the heat will be over two or three days, with the final hot day also on Monday. Melbourne could be in for another 40 degree day again, before a stormy cool change that evening sends the mercury plummeting.

Further east, heat will linger in Canberra, with temperatures in the mid-to-high 30's each day from Boxing Day to New Years Eve. Overnight temperatures will remain high from Sunday onwards.

For Sydney, mild but humid conditions will stick around a while longer, with the heat arriving on Monday 30th. At this stage it could be a hot start to New Years Eve, with a gusty southerly, a few showers and the odd rumble adding to the entertainment bill.