Specifically, on Tuesday the highest temperatures will reach 

a. In continental areas 39 to 41 and locally in the west and north 42 degrees Celsius.
b. In the Ionian, the Dodecanese and southern Crete, 37 to 38 degrees Celsius.
c. In the rest of the islands, 33 to 35 degrees Celsius.
d. In Attica (Athens) and the prefecture of Thessaloniki, 38 to 39 degrees Celsius

On Wednesday and Thursday the maximum temperature will reach

a. In the interior of the mainland 41 to 42 and locally in the west, central and north 43 degrees Celsius.
b. In the Ionian, the islands of the Eastern Aegean, the Dodecanese and southern Crete are 38 to 40 degrees Celsius.
c. In the rest of the island country, 35 to 37 degrees Celsius.
d. In Attica (Athens) and the prefecture of Thessaloniki, 39 to 40 degrees Celsius