Athens is located at a transition point between the Mediterranean and the Alpine climatic zones. The city enjoys a typical Mediterranean climate, with the greatest amounts of precipitation mainly occurring from mid-October to mid-April; any precipitation is sparse during summer and falls generally in the form of showers and/or thunderstorms. Because it is located in a strong rain shadow, however, Athens is very dry compared with most of Mediterranean Europe. The mountainous northern suburbs, however, experience a somewhat differentiated climate with generally lower temperatures and more considerable snowfalls in winter. Fog is highly unusual at the city centre but is more frequent to the east, behind the Hymettus mountain range.
Snowfalls occur in an almost yearly basis, though these do not normally lead to significant if any disruptions at all. Nevertheless, the city has experienced its share of blizzard-like conditions, demonstrated in severe episodes that, in fact, tend to become more and more often in this current decade. The most recent examples include the blizzard of March 1987, February 1992, January 2002, February 2004 and January 2006 all dumping heavy amounts of snow that literally blanketed the entire metropolitan area for days.
Spring and autumn are considered ideal seasons for sightseeing and indeed for all kinds of outdoor activities.
Summers can be particularly hot and at times prone to smog and pollution related conditions (admittedly, however, much less so compared to the past). The average summer daytime maximum temperature is 32°C. Heat waves are not too common and mostly happen during the months of July and/or August, when hot air masses come to Greece from the south or the south-west. It is only on such days that temperature maxima shoot over 38°C.
The all time high temperature for the metropolitan area of Athens is +45.0°C and was measured at the Nea Filadelfia suburb (July 2000, HNMS station), while the respective low temperature record is -10.4°C and was measured at the Votanikos area, close to the city centre. In February 2004, temperatures plummeted to -7°C at the University Campus and to -10.1°C at the meteorological station of the National Observatory of Athens in Penteli.