Late spring and early autumn is the best time to visit Portugal. April and May can offer activities like diving and mountain biking. This time is also suitable for exploring Douro Valley or Parque Natural da Serra da Estrela. During the summer months, the country gets more crowded. The prices reach their peak in August due to summer holidays in most European countries. With an arrival of mild October, the crowds thin out, but the ocean water stays warm. The country is quite rainy from November through March but sightseeing, surfing and hiking during this period is fantastic!