As the wettest place in one of the most notoriously rainy regions of the country, Olympic National Park doesn’t necessarily have a “dry” season, though summer can be considered “less wet.” In general, most visitors will want to come sometime between May and October. The peak of summer—July to September—offers the driest, warmest conditions, with temperatures topping out in the mid 70s. Near the coasts and in the lower forests, winters (November through March) are perpetually wet, with relatively mild temperatures in the 30s or 40s. Heavy winter snowfall is the norm among the interior mountains.
Outdoors-people with a penchant for fishing won’t want to miss out on catching massive salmon and steelhead. Fall not only brings new leaf colors, but also marks the return of salmon to the Olympic Peninsula rivers, while steelhead season starts about a month later. You don’t need a license to fish the catch-and-release rivers in Olympic National Park, but you do need a state record card (available at most ranger stations or tackle shops, and online with the Department of Fish and Wildlife).
Another worthy seasonal attraction in Olympic National Park is its prolific alpine wildflower bloom, perfect for photographers. July is the best time to see tiger lilies, red columbine, and other blooms in high-country areas like Hurricane Ridge.