What’s the weather going to be like?

How can meteorologists predict the weather? Do they have a crystal ball?

No. Their predictions are based on meteorology, the science that studies the atmosphere and weather.

Meteorologists use images they receive from artificial satellites orbiting the Earth. They analyse these images for information about cloud movements, clear areas, or the temperature in the upper part of the atmosphere.

Meteorologists also use information about temperature, precipitation, wind, etc. from weather stations all over the world, including weather stations on boats.

However, factors such as clouds and winds can change suddenly, which means meteorologists have to change their forecasts. For this reason, only weather forecasts for the next few days are very reliable.

The Cantabrian, the Mediterranean, and the Atlantic watersheds are the three main watersheds in Spain.

The Cantabrian watershed

This includes all the rivers that flow into the Cantabrian Sea. These rivers are short, and have a regular and abundant flow because rainfall in this area is frequent throughout the year. The main rivers of this watershed are: the Navia, the Nalón, the Eo, the Nervión and the Bidasoa.

The Atlantic watershed

This includes all the rivers that flow into the Atlantic Ocean.

It is the largest watershed in Spain.

• The rivers of Galicia. These are short rivers with an abundant flow and a regular flow regime. The longest rivers are the Miño and its tributary, the Sil.
• The rivers of the Inner Plateau. These are long rivers, but have an irregular flow regime with a lower flow in summer. The main rivers are the Duero, the Tajo and the Guadiana.
• The rivers of Andalusia. These are short rivers with a low flow and an irregular flow regime, except for the Guadalquivir.

There are no rivers in the Canary Islands. When it rains heavily, water flows through deep channels called gorges.

The Mediterranean watershed

This includes all the rivers that flow into the Mediterranean Sea. Except for the Ebro, these rivers are short and carry little water because they flow through areas with low rainfall. They have an irregular flow regime: a low flow, or even drought in the summer, and a high flow, or even flooding in spring and autumn.

Spain has four main types of climate: Oceanic, Mountain, Subtropical and Mediterranean.

Oceanic climate

This is the climate of the north of the Iberian Peninsula, including Galicia, Asturias, Cantabria, the Basque Country, Navarre, the north of Aragón, and Castile and León.

These are its main characteristics:

• Temperatures are warm in summer and mild in winter due to the proximity of the sea.
• Precipitation is abundant and regular throughout the year.

Vegetation is abundant. It consists of forests with oak, chestnut and beech trees, and meadows.

Mountain climate

This is the climate of mountainous regions above 1,500 metres.

These are its main characteristics:

• Temperatures are cool in summer and very low in winter.
• Precipitation is abundant. It often snows in winter.

Vegetation is scarce. At higher altitudes, it consists of meadows. In lower areas, there are forests with pine, oak and fir trees.

Subtropical climate

This is the climate of the Canary Islands. This is the only region of Spain that has a subtropical climate.

These are its main characteristics:

• Temperatures are mild throughout the year and do not vary much.
• Precipitation is higher in the northern parts of the islands. In contrast, it is scarce in the south of the islands and in the islands closest to Africa, such as Lanzarote and Fuerteventura.

The vegetation includes laurel forests, Canary Island pines, palm trees and dragon trees. There are some species that are unique to this area, known as endemic species, such as the Teide violeT.

Mediterranean climate

The Mediterranean climate is the most common climate in Spain.

There are three variations:

• Typical Mediterranean climate. This is the climate of the Balearic Islands, most of the Mediterranean coast and a few inland areas of the Iberian Peninsula.Temperatures are high in summer and mild in winter. Precipitation is scarce and irregular. Rainfall is highest in spring and autumn. Drought is common in summer.
• Continental Mediterranean climate. This is the climate of most inland areas of the Iberian Peninsula, and part of Catalonia and Andalusia. Temperatures are high in summer and low in winter. Precipitation is scarce. It sometimes snows in winter.
• Dry Mediterranean climate. This is the climate of the southeastern areas of the Iberian Peninsula. Temperatures are mild along the coast and extreme inland.Precipitation is very scarce throughout the year, with extremely dry summers.

Vegetation is diverse, but scarce. It mostly consists of shrubs, rockrose and thyme, and forests with holm oaks, cork oaks and pine trees.

Mediterranean watershed

Rivers in this watershed have a low and irregular flow because of droughts in summer. The main rivers, from east to west, are the Po, the Rhone and the Ebro.    

Black Sea watershed

Rivers in this watershed are very long with a high flow, so they are navigable by boat. The main rivers, from east to west, are the Dnieper, the Dniester and the Danube.

Caspian Sea watershed

Rivers in this watershed are long with a high flow, including the longest river in Europe, the Volga.

Temperate climates

Most of Europe is located between the latitudes of 35ºN and 60ºN. These latitudes are within the temperate zone of the Earth. This means that most of Europe does not have very high or very low temperatures.

In Europe, the following temperate climates can be found: 

• Oceanic climate. This is the climate of areas along the Atlantic Ocean and central Europe. Temperatures are mild in summer and low in winter. Precipitation is abundant and regular.
   
• Mediterranean climate. This is the climate of Mediterranean coastal areas and some inland areas of southern Europe. Temperatures are high in summer and mild in winter. Precipitation is low, especially in summer.

Cold climates

Cold climates can be found in latitudes above 60ºN and in areas with high altitude.

There are two types of cold climate:

• Polar climate. This is the climate in the north of the Scandinavian countries and Russia. It is the coldest climate on Earth. Temperatures are very low, under 0º C for most of the year. Precipitation is scarce.

The vegetation of Europe

Europe has varied landscapes with different vegetation.

• Vegetation in temperate regions. There are three types:

– In areas with an Oceanic climate, there are meadows and forests with beech and oak trees.
– In areas with a Mediterranean climate, there are forests with holm oaks, cork oaks, and bushes, such as rockrose and rosemary.
– In areas with a Continental climate, there are forests with evergreen trees such as firs and pines, known as taigas, and plains with poor soil where only grasses can grow, known as steppes.

• Vegetation in cold regions. In areas with a Polar climate, vegetation is very scarce. In the warmest areas, mosses, lichens and small shrubs grow. This vegetation is known as tundra.