Redwood National Park in September

Late spring through early fall gives you the best weather, but each season has its perks. May through October offers the warmest temperatures and clearest trails, with July and August being peak season. But here's the thing about summer – the coast stays cool and foggy while inland areas can hit 80 degrees. Fall is actually ideal because the fog lifts more often, giving you better photos and warmer hiking conditions. Winter brings heavy rain that can close some trails, but the storms also clear the air for incredibly dramatic forest scenes. Plus, winter is when you're most likely to spot Roosevelt elk during mating season. Spring wildflowers bloom in the prairies from March to May. Avoid major holiday weekends if you want solitude – the popular groves can feel like parking lots during Memorial Day and Labor Day.