People enjoy a cool dip at a beach in Nafplio in the northeastern Peloponnese earlier this week. [Vangelis Bougiotis/InTime News]

Greece faced another day of scorching heat Tuesday, with temperatures threatening to hit 40 degrees Celsius in some areas before a welcome cooldown later in the week.

The National Meteorological Service forecast highs of 37-38C across much of the mainland, climbing to 39-40C locally. Athens was expected to reach 38C, although coastal areas should be 2-3 degrees cooler.

The islands offered only limited relief, with highs of 34-36C and up to 37C in parts of the eastern Aegean. Strong northerly winds reaching 7 Beaufort were expected in the Aegean.

Mostly clear skies will prevail, though the heat could give way to brief showers and isolated thunderstorms over mountainous areas, particularly in northern Greece.