Greece has mild, wet winters and hot, dry summers.
Athens daytime summer temperature averages 90Â°F and often exceeds 100Â°F for periods in July-August. Humidity is low and the heat is tempered by sea breezes. Summer evenings are comfortable outdoors. Spring and fall temperatures are pleasant, and winter temperatures are 30Â°-55Â°F. Snow flurries occur, particularly in the northern suburbs, but seldom accumulate. Air pollution is a major problem in Athens throughout the year, but the climate is otherwise healthy.
Thessaloniki, in northern Greece, experiences high temperatures and humidity from the end of May until the end of September. Summer heat is sometimes tempered by late morning and early evening breezes. July and August nights can be uncomfortably warm. In winter, periods of mild, sunny, and spring-like weather are interspersed with uncomfortable cold periods. Thessaloniki has periods of chilly and damp weather, with considerable rainfall and occasional snow. Temperatures often fall below freezing in winter. Although snow does not linger, the city has been struck by blizzards. One feature of Thessalonikiâ€™s climate is the vardari, a strong northwesterly wind that appears suddenly and irregularly from the area of the Axios (Vardar) River Valley.