Despite of the fact that the Algarve has a homogeneous annual climate, actual weather conditions may significantly differ in the various locations due to the winds on the Atlantic coast. In the summer the sea in the Eastern Algarve is usually warmer than in the western part of the Algarve because of the Mediterranean winds from the Levant. Especially iduring the winter time wind and waves will be considerably rougher on the Western coast.
The Algarve's geographical position on Europe’s westernmost tip in the south of Portugal gives it some special bioclimatic features. Although situated by the Atlantic Ocean, it has a temperate climate with Mediterranean characteristics, more than 3,000 hours of sunshine per year and a low annual average rainfall, mainly during the winter months. Even in the hottest days in July and August a mild breeze from the Atlantic provides relief.
Source: "Algarve weather and climate" - algarve-portal.com