Peneda-Gerês National Park in March

Late spring through early fall offers the best conditions. May brings wildflowers and flowing waterfalls, while September delivers warm days without summer crowds. July and August see the most visitors, particularly Portuguese families on holiday. Winter brings snow to higher elevations and closes some mountain roads. But it's also when you'll have the trails mostly to yourself. The Homem River valley stays accessible year-round and offers dramatic winter landscapes. Avoid major Portuguese holidays if you want solitude. Easter week and August 15th bring traffic jams to normally quiet mountain roads. Weather can be unpredictable any time of year. Check forecasts before heading to higher elevations, and be prepared to turn back if conditions deteriorate.