The Spanish mainland is bordered to the south and east almost entirely by the Mediterranean Sea (except for the small British territory of Gibraltar); to the north by France, Andorra, and the Bay of Biscay; and to the west by the Atlantic Ocean and Portugal.

In the extreme south of Spain's mainland lie the Straits of Gibraltar, which separate the Iberian peninsula and the rest of Europe from Ceuta and Morocco in North Africa.

[citation needed] The Canary Islands, geographically and geologically part of the African continent, are located in the Atlantic Ocean.

[5] Most of Spain's peninsular region consists of the Meseta Central, a highland plateau rimmed and dissected by mountain ranges.

[3] Despite their height, however, the mountain system does not create a major barrier between the northern and the southern portions of the Meseta Central because several passes permit road and railroad transportation to the northwest and the northeast.

[3] The Cordillera Cantábrica, a limestone formation, runs parallel to, and close to, the northern coast near the Bay of Biscay.

[3] The mountains exceed 2,000 m in their northern region and reach a maximum height of over 2,300 m east of the headwaters of the Rio Duero.

[3] The Andalusian Plain is bounded on the north by the Sierra Morena and on the south by the Sistema Penibético; it narrows to an apex in the east where these two mountain chains meet.

[3] Minor low-lying river valleys close to the Portuguese border are located on the Tagus and the Río Guadiana.

[3] The narrowest coastal plain runs along the Bay of Biscay, where the Cordillera Cantábrica ends close to shore.

[3] Most major rivers rise in the mountains rimming or dissecting the Meseta Central and flow westward across the plateau through Portugal to empty into the Atlantic Ocean.

[3] Rivers in the extreme northwest and in the narrow northern coastal plain drain directly into the Atlantic Ocean.

[3] The major rivers flowing westward throughout the Meseta Central include the Duero, the Tagus, the Guadiana, and the Guadalquivir.

Water scarcity is a significant issue in many regions throughout Spain and climate change may aggravate the problem, with longer periods of dry weather.

[9] The locally generated steppe climate covers the majority of peninsular Spain, influencing the Meseta Central, the adjoining mountains to the east and the south, and the Ebro Basin.

[9] This climate is characterized by wide diurnal and seasonal variations in temperature and by low, irregular rainfall with high rates of evaporation that leave the land arid.

[9] A maritime climate prevails in the northern part of the country, from the Pyrenees to the northwest region, characterized by relatively mild winters, warm but not hot summers, and generally abundant rainfall spread out over the year.

[9] The high humidity and the prevailing off-shore winds make fog and mist common along the northwest coast; this phenomenon is less frequent a short distance inland, however, because the mountains form a barrier keeping out the sea moisture.

[9] The Mediterranean region is marked by Leveche winds—hot, dry, easterly or southeasterly air currents that originate over North Africa.

[9] A cooler easterly wind, the Levante, funnels between the Sistema Penibetico and the Atlas Mountains of North Africa.