Athens sprawls across the central plain of Attica, often referred to as the Attica Basin which is bound by Mount Aegaleo in the west, Mount Parnitha in the north, Mount Penteli in the northeast, Mount Hymettus in the east, and the Saronic Gulf in the southwest. The capital has expanded to cover the entire plain, making future growth difficult.

Processed 3D view of the Attica Basin from space. Courtesy: NASA

The geomorphology of Athens causes the so-called temperature inversion phenomenon, and along with the failure of the Greek Government to control industrial pollution is responsible for the air pollution problems the city has recently faced.[9][10] (Los Angeles and Mexico City also suffer with similar geomorphology inversion problems).[10] The pollution of Athens was at one point so destructive, that according to the then Greek Minister of Culture, Constantine Trypanis, the carved details on the five caryatids of the Erechtheum have seriously degenerated, while the face of the horseman on the Parthenon's west side is all but obliterated.[11] A series of strict measures then taken by the authorities of the city throughout the 1990s resulted in a dramatic improvement of air quality; the appearance of smog (or nefos as the Athenians used to call it) has become an increasingly rare phenomenon.

Climate

Athens 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. Due to its location in a strong rain shadow because of Mount Parnitha , however, the Athenian climate is much drier compared to most of the rest of mediterranean Europe . The mountainous northern suburbs, for their part, experience a somewhat differentiated climatic pattern, with generally lower temperatures and more substantial snowfalls during winter. Fog is highly unusual in the city centre but it is more frequent to the east, behind the Hymettus mountain range.

Snowfalls occur almost on a yearly basis, though these do not normally lead to significant, if any, disruption. Nonetheless, the city has experienced its share of heavy snowfalls, not least in the past decade; during the blizzards of March 1987, February 1992, January 2002, February 2004 and January 2006, snow literally blanketed large parts of the metropolitan area, causing havoc across many suburbs of the city.

Spring and fall (autumn) are considered ideal seasons for sightseeing and all kinds of outdoor activities. Summers can be particularly hot and at times prone to smog and pollution related conditions (however, much less so than in the past). The average daytime maximum temperature for the month of July is 92.3 °F (33.5 °C) and heatwaves are relatively common, occurring generally during the months of July and/or August, when hot air masses sweep across Greece from the south or the southwest. On such days only temperature maxima soar over 100 °F (38 °C).

The all-time high temperatures for the metropolitan area of Athens of 48.7 °C (119.7 °F) and 48.0 °C (118.4 °F) were recorded at the Tatoi and Elefsina suburbs on July 10, 1977 (HNMS-http://records.e-kairos.com/) and are also Greece's all-time high temperatures. The respective low-temperature record is -10.4 °C (13.3 °F), recorded at the Votanikos area, close to the city centre. During the February 2004 blizzard (one of the worst snowstorms ever to hit the city), temperatures plummeted to -7.0 °C (19.4 °F) at the University Campus, and -10.1 °C (13.8 °F) at the meteorological station of the National Observatory of Athens, in Penteli


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Pollution & Environment

Air pollution remains to some degree an issue for Athens, particularly on the hottest summer days. Nevertheless, widespread measures taken by the authorities throughout the 1990s have dramatically improved air quality. In late June 2007, the Attica region experienced a number of brush fires, including one that burned a significant portion of a large forested national park in Mount Parnitha - considered critical to maintaining better air in Athens all year round. Damage to the park has led to worries over a stalling in the improvement of air quality in the city.

Athens tap water is safe, and of very good quality. It is comparable to or exceeds the quality of the best US city water systems sourced from higher elevations, and is considered one of the best municipal waters in Europe and worldwide.