Late June through August offers peak sunny weather and blue skies, perfect for hitting the beach. For thinner crowds and cooler (but still nice) temperatures, go in the spring or early fall. Every year, millions of tourists flock to Portugal to enjoy its beaches, wine, and festivals. As a resident, I can attest to the country's bounty of activities, history, and delicious food—don't miss the pastéis de nata (sweet custard tarts) or bacalhau (dried and salted cod). “Portugal is one of the smallest countries with the largest plethora of touristic activities on offer,” says Nick Roucos, managing director of Bomporto Hotels, which manages The Vintage Lisbon and The Lumiares .…