in January normally average in most of the Mediterranean region, and they are colder in the northeastern coastal area near Barcelona. In winter, temperatures inland in the Andalusian Plain are slightly lower than those on the coasts. Temperatures in July and August average on the coast and farther inland, with low humidity. The Mediterranean region is marked by Leveche winds—hot, dry, easterly or southeasterly air currents that originate over North Africa. These winds, which sometimes carry fine dust, are most common in spring. A cooler easterly wind, the Levante, funnels between the Sistema Penibetico and the Atlas Mountains of North Africa. Cities and population geography The most populous cities in Spain are Madrid (3.3 million), Barcelona (1.6 million), Valencia (790,000), and Seville (690,000; all data as of 2019). Resources and land use Natural resources: coal, lignite, iron ore, uranium, mercury, pyrites, fluorspar, gypsum, zinc, lead, tungsten, copper, kaolin, potash, sepiolite, hydropower, arable land Land use: Arable land: 27.18% Permanent crops: 9.85% Other: 62.97% (2005) Irrigated land: 38,000 km2 (2003) Total renewable water resources: 111.1 cubic metres (2005) Freshwater withdrawal (domestic/industrial/agricultural): total: 37.22 cu km/yr (13%/19%/68%) per capita: 864 cu m/yr (2002) Environmental concerns Natural hazards: periodic droughts, occasional flooding Environment – Current Issues: Pollution of the Mediterranean Sea from raw sewage and effluents from the offshore production of oil and gas; water quality and quantity nationwide; air pollution; deforestation; desertification Environment – International Agreements: Party to: Air Pollution, Air Pollution-Nitrogen Oxides, Air Pollution-Sulphur 94, Air Pollution-Volatile Organic Compounds, Antarctic-Environmental Protocol, Antarctic Treaty, Biodiversity, Climate Change, Climate Change-Kyoto Protocol, Desertification, Endangered Species, Environmental Modification, Hazardous Wastes, Law of the Sea, Marine Dumping, Marine Life Conservation, Ozone Layer Protection, Ship Pollution, Tropical Timber 83, Tropical Timber 94, Wetlands, Whaling Signed, but not ratified: Air Pollution-Persistent Organic Pollutants Maritime claims Contiguous zone: Exclusive economic zone: with (applies only to the Atlantic Ocean) Territorial sea: See also Autonomous communities of Spain Comarcas of Spain Extreme points of Spain Provinces of Spain Topographical relief of Spain References Citations Sources External links Spanish official cartography, including National Topographic Maps MTN50 and MTN25