Ordesa National Park in January

May through October is your window, but each month has its personality. May brings wildflowers and fewer crowds, but some high trails stay snow-covered. June hits the sweet spot — warm days, cool nights, and waterfalls at full power from snowmelt. July and August mean peak crowds and scorching midday heat, but also the longest days and most reliable weather. September is magic hour — golden light, comfortable temperatures, and the tourist hordes have gone home. October can be spectacular with autumn colors, but weather becomes unpredictable and some facilities close. Winter transforms the park into a snow-covered wonderland, but most trails become inaccessible without serious mountaineering gear.