The only continent on the planet which does not wilderness on its territory is Europe. Many factors prevent the formation of deserts on the continent.
Perhaps one of the most important is its geography. The fact is that Europe is located too far from the northern tropical circle and therefore the equator. Another important factor is the presence of relatively warm water bodies around Europe.
For example, in the Atlantic Ocean to the northern part of the continent runs the warm Gulf Stream. It bears on the continent very heavy rainfall, because as we know, the warm ocean waters cause very strong fumes.
These vapours fall in the form of rainfall over the British Isles, Scandinavia and Northern Europe. Atlantic influence and southern Europe, but relatively weak.
From Southern European countries the Atlantic causes strongest influence on climate conditions of Portugal and less in Spain. In the rest of Southern Europe more important is the impact of the warm Mediterranean.
It makes autumn and winter fairly moist and protects the southern parts of the continent from deserts formation, although summers are very long, hot and dry. Relief has also very strong influence.
In the southern part of the continent it is predominantly mountainous. Mountains traditionally have more humid climate and attract to themselves vapours and help forming of rain clouds.
Precipitations, which fall over the mountains create countless small rivers that irrigate large areas.