The climate of Spain is highly diverse and varies considerably across the country's various regions. In fact, Spain is sometimes described as the most climatically diverse country in Europe and has 13 different Köppen climates.
The four most dominant climates in the country include: The hot-summer Mediterranean climate (Csa), the warm-summer Mediterranean climate (Csb), the semi-arid climate (BSk) and the oceanic climate (Cfb).
The average annual temperature in the mainland varies from less than in the north of the Pyrenees, close to the border with France, to more than . on small regions of Mediterranean coast on Almeria, Granada and Malaga provinces, reaching as high as in Rincón de la Victoria. The annual average precipitation ranges from more than on the northwest of Galicia and in the Pyrenees near San Sebastián to less than in southeastern Spain in Cabo de Gata-Níjar Natural Park.
In the Canary Islands, annual average temperature varies from less than in the highest altitude area of Santa Cruz de Tenerife to more than on lower areas of Santa Cruz de Tenerife, while the average annual precipitation ranges from more than on the highest altitudes of La Palma to less than in parts of Lanzarote and Fuerteventura.
Spain, like other countries of the Mediterranean Basin, is vulnerable to climate change, with greater risk of heatwaves and dry weather.
Zones Four main climatic zones can be distinguished, according to the country's Köppen-Geiger climate classification and orographic conditions: The hot-summer Mediterranean climate (Csa) which is also characterized by dry and warm/hot summers and cool to mild and wet winters. According to the Köppen climate classification, this climate is dominant on the Iberian Peninsula, particularly the variety with summer droughts, covering all but the far northern part of the country where the Oceanic climate predominates. The hot-summer Mediterranean climate covers coastal areas (excluding the northern Atlantic coast and southeast Mediterranean coast), the Guadalquivir river basin and the lower reaches of the Tagus and Guadiana basins to the west of the country. It also extends to parts of the interior of the Valencian Community, Castilla-La-Mancha and Catalonia. The warm-summer Mediterranean climate (Csb) which predominates in parts of northwestern Spain and mostly inland in central-northern Spain at altitudes above 900-1000 masl. The semi-arid climate (BSh and BSk) is predominant in the south eastern part of the country (Almeria province in Eastern Andalusia, Murcia region and Alicante province in Southern Valencia) and in the middle reaches of the Ebro valley to the north east (Zaragoza province), reaching as far west as southern Navarre. It is also present in large areas of the central table lands (primarily in Madrid and in the La Mancha region which includes parts of Cuenca, Guadalajara, and Toledo provinces) and some of the driest areas of Extremadura. In contrast to the Mediterranean climate, the sunny season continues beyond the end of summer and the vegetation is less dense. The oceanic climate (Cfb) is located in the northern part of the country, especially in the regions of Galicia, Basque Country, Asturias, Cantabria, and Navarre. Apart from the four main climate zones, other noticeable sub-zones can be found, such as the humid subtropical climate in large areas in the northern half of Catalonia going down to Barcelona, the province of Huesca and northern Navarre. The warm-summer humid continental climate (Dfb) which can be found in many areas in north-eastern Spain, in areas starting with altitudes above 1000-1100 masl. It can be found also in some areas in the Cantabrian Mountains and the highest areas of the Sistema Ibérico mountain range in central-eastern Spain. The dry continental climates all across Spain in the highest areas (notably in the Sierra Nevada and the highest areas in central-northern Spain), the alpine climate and the Subarctic climate in the higher areas of northern Spain's various mountain ranges (notably the Cantabrian Mountains and the Pyrenees) and a hot desert climate in the southeastern coastline, on Almeria and Murcia provinces. Hot desert climates and hot semi-desert climates can also be found in the Canary Islands, most notably on the islands of Lanzarote and Fuerteventura, but also in the coastal areas of Gran Canaria and in the south of Santa Cruz de Tenerife. On the remaining islands, this climate is also present, but in a much smaller portion. In the coastal areas of the Canary Islands, there are some regions that are influenced by a tropical climate, as the average temperature in the coldest month is above .
Hot summer Mediterranean climate The hot-summer Mediterranean climate (Csa) is found in many parts of Spain's Mediterranean coast, from the border with Portugal to the middle of the province of Granada. Then it starts in Calpe, and goes to the border with France (with some exceptions such as the city of Valencia). It also extends inland in Andalusia and Extremadura. It is characterized by hot, dry summers and mild winters with infrequent frosts. The summers are hot, the winters are mild and most of precipitation falls in the autumn. Examples of cities with Csa climate are Málaga, Barcelona, Palma or Seville.
Warm summer Mediterranean climate The Csb warm-summer Mediterranean climate is found in parts of Galicia and the western areas of Castilla y Leon. Coastal Mediterranean region is marked by Leveche winds: hot, dry, easterly or southeasterly air currents that originate over North Africa. Periods of these winds, which sometimes carry fine Saharan dust, are more common in spring and are associated with a sudden, usually short-lived, increase in temperature. A cooler easterly wind, the Levante, funnels between the Sistema Penibético and the Atlas Mountains of North Africa. These easterly winds are the ones which most influence the Mediterranean climate. The most populous city with Csb climate in Spain is Vigo. Other cities with this climate are Ávila, León and Salamanca.
It is characterised by year-round mild temperatures with drier summer months, often resulting in moderate drought conditions with at least one month per year usually recording less than . Cool ocean currents, upwelling and higher latitudes are often the reason for this cooler type of Mediterranean climate. Winters in this zone are rainy and can be mild to chilly. Some locales in this zone experience some amount of snowfall, while others do not. Annual rainfall is higher than in the eastern and southern regions, usually ranging from . Not all Galicia has a Csb climate, most of the north and central mountains have a typical oceanic Cfb. Some valleys in the south are classified as Hot-summer Mediterranean (Csa), like the comarca of O Condado, the city of Ourense or O Ribeiro.
In North-West Castile, the climate is classified also as Csb because the temperatures of summer are cooler due to the altitude.
Oceanic climate An oceanic climate prevails from the Pyrenees to Galicia, area which is sometimes called "Green Spain", characterized by relatively mild winters and warm summers. The climate and landscape are determined by the Atlantic Ocean winds whose moisture gets trapped by the mountains circumventing the Spanish Atlantic coast. Because of the Foehn effect, the southern slopes fall inside the rain shadow zone and so Green Spain contrasts starkly with the rest of Spain. The rainfall is generally abundant, exceeding and is fairly evenly spread out over the year, with the driest month above , which is the minimum criteria for an oceanic climate according to Köppen. Although Köppen officially limits the oceanic domain to the Asturias and the Basque Country region, certain authors such as Trewartha prefer to extend this climatic zone to the north-west part of the peninsula to Galicia, due to the moderate summer temperatures.
Temperatures vary only slightly, both on a diurnal and a seasonal basis, and averages range from in January to in July. The moderating effects of the sea are less prominent further inland, where temperatures are more extreme than those on the coast. Distance from the Atlantic Ocean also has an effect on precipitation levels, so there is less rainfall in the east than in the west. Autumn (October to December) is the wettest season, while July is the driest month. The high humidity and the prevailing off-shore winds make fog and mist common along the north west coast; this phenomenon is less frequent a short distance inland because the mountains form a barrier to the maritime moisture.
Humid subtropical climate The humid subtropical climate exists in large areas of north-eastern Spain, mostly in the northern half of Catalonia and the province of Huesca. This climate is also found across northern Navarra and the northern areas of the province of Guadalajara. The climate usually occurs in the transition zone between the oceanic climates further north and the mediterranean climates further south. The largest city with this climate in Spain is Girona.
This type of humid subtropical climate is atypical for normal humid subtropical climates, with there not being the characteristic inflow of warm, moist air during summer causing convective thunderstorms but is nonetheless classified as humid subtropical by Köppen.
Semi-arid climates The semi-arid climate (BSh and BSk in the Köppen climate classification) is predominant in south-eastern Spain (covering most of Alicante, Murcia and Almería provinces), and in certain parts of the Ebro Valley. It is also present in parts of the centre (Madrid, Toledo, Ciudad Real and Albacete provinces), south and west of the country which borders between a Mediterranean and semi-arid climate. It is very hot during the summer (temperatures can exceed ) and the drought usually extends into the autumn. Rainfall in these areas are usually between 200 mm and 500 mm.
Desert climate The desert climate exists in a few heavily rain-shadowed zones of the south-eastern coast of Spain and in many parts of the Canary Islands. Within mainland Spain, it appears predominantly in Almería, with the city of Almería bordering a hot desert climate categorization (Köppen: BWh) as the average temperature is and the average precipitation is approximately 200mm. This area extends to the Andarax and Almanzora river valleys and the Cabo de Gata-Níjar Natural Park, which are also known for having also a hot desert climate (Köppen: BWh), with a precipitation amount of per year which is reportedly the driest place in Europe. In fact, Almeria, Murcia and Alicante provinces are the only areas in Europe within the hot desert climatic zone. The desert climate exists in other areas of the southeast, such as the Tabernas Desert. It also exists in areas of Murcia and specific points inland of the province of Alicante.
Other types Besides the above three major climate zones, there are four other climate types in Spain:
The mountainous climate is present in the Picos de Europa, Sistema Central, Sistema Ibérico, Pyrenees and Sierra Nevada, qualified as an Alpine climate, Spain's major mountain systems. The low-lying areas of the Canary Islands have influences of tropical climate in terms of temperature, this being mild and stable () throughout the year. Most of the islands have hot desert climates or hot semi-desert climates, and a low altitude areas have tropical steppe climates, like the cities of Santa Cruz de Tenerife, Las Palmas de Gran Canaria or La Palma. In terms of precipitation, the eastern islands are arid while the westernmost ones are semi-arid and receive more rainfall, with some very wet areas in the mountains of La Gomera, La Palma and Tenerife, home to the cloud forest known as laurisilva. The easternmost islands are arid with Saharan climate moderated by the Atlantic Ocean.