Melbourne and Adelaide will finally see their final day of heat of the current hot spell today as a trough and associated front push through the cities over the next 12 hours. However, both places should experience their hottest day of this spell as dry northerly winds develop ahead of the trough. Including today, the current hot spell has seen Adelaide reach at least 30 degrees for the last seven days, and 35 degrees for the past four days. Adelaide will see the mercury soar again today, reaching 39 degrees, with 40 degrees not out of the question. At 10am the city had already reached 35 degrees after a very warm night when it dipped to just 26, which is nine degrees above average. Relief will finally come for Adelaide residents in the early evening as a southwesterly change moves through, bringing noticeable cooling. However, the change should be generally dry with only a slight risk of a thunderstorm. Melbourne is set to reach 35 degrees today, which would make it the sixth day in a row the mercury has climbed above 30 degrees. This is the first time this has occurred since 2009. The city will have to endure a very warm night before a cooler change moves through around sunrise on Tuesday which may be associated with showers and thunderstorms. Cooling will only be gradual as the warm air mass lingers, with the city set to still reach 28 degrees. In the wake of the front, temperatures will remain a couple of degrees above average in Melbourne, and be close to average in Adelaide. The slightly cooler conditions will only be short lived, with temperatures rising into the 30's again for both cities later this week.