In Greece there are great differences in temperature from region to region. And this is because of its geographical position and the alternation of land and sea. The differences from region to region are smaller during summer.
During the winter from south to the north, the temperature drops slower on the west coasts making them warmer.
Generally on the coasts and islands , the winters are milder and the summers cooler compared to areas in Greece's mainland.
The summer in the lowlands and plains makes great hot. Especially at midday the temperature usually ranges from 32 to 36 degrees Celcius but often reach 40 degrees.
The rising of the temperature is starting to be felt from March. Warmest month is July with the exception of Cyclades, western Greece and the Ionian Islands, where the warmest month is August.
On annual basis, the relative humidity has the highest rate of an average 72,5% in northwestern Greece ( Epirus and Corfu ) and in other islands near the coast of Asia Minor. The lowest humidity level of 65% is noted in Attica, Cyclades, Eastern Peloponnese, Kythira and to some extent, from the northeast to the south coasts of Crete.
In all regions the average relative humidity reaches its peak in December and the lowest in July and in some areas in August. The summer months in Eastern Greece the relative humidity goes down to its lowest point and the dryness of the air reaches its highest. The low humidity of summer is beneficial for autumn when the humidity begins to rise again. This dryness makes the atmosphere clear and gives the sky a blue color.
Greece has a slight cloudiness as Southern France, the French Riviera and Spain. The clouds constantly decreasing as we are going from the highlands of country's interior to its peninsulas and coasts. Less cloudiness in Western Cyclades, Attica, Western Crete, Lakonia in Southern Peloponnese, Argolida in Eastern Peloponnese and the west coast of the Peloponnese bordering the Ionian Islands.
Less cloudiness occurs in July and August. During these two months in Cyclades and generally in Southeastern Greece, the cloudiness is minimal to no existent. All over Greece however, these two months we have more hours of sunshine.
In general, sunshine in Greece is high. In its peak, 3.000 hours per year, in the south and west Aegean and its islands. To the coast of Western Crete, to Kythera, in the southern coast of Peloponnese, in the coasts of Argolida and South Ionian. Also on islands near the coasts of Asia Minor and North Aegean.