Weather in Redwood National Park is fairly consistent year-round, with temperatures bottoming out in the high 30s in January and peaking in the mid-60s at the height of summer—but daytime temps in the middle of winter can reach up to the mid-50s. Expect rain (after all, the trees do have to grow), especially from October through April. The rest of the months, fog is more likely.
Summer is the most popular time for tourists, and although carloads descend on the park during this time, it’s expansive enough to keep it from feeling too crowded. There are no lodging options within the park itself, but there are plenty of campsites. If you prefer a roof over your head, nearby towns like Arcata, Eureka, and Crescent City offer that in spades—try the Curly Redwood Lodge if you want to sleep in a motel constructed entirely from the lumber of just one redwood.
For an infusion of color, springtime offers rhododendrons in full bloom, while fall produces some autumnal hues (although not as vibrant as you’d find farther east). To see the tallest of the tall, head to aptly named Tall Trees Grove, where the Libbey Tree stretches up some 360 feet, one of the world’s tallest living things. It’s not easy to get here—car access is limited; permits must be obtained from the Thomas H. Kuchel Visitor Center; and it involves a 45-minute drive, a combination lock, and a 1.3-mile hike—but if you want to experience being completely awed by nature, this grove is the place.
The national park, which is free to enter (the nearby state parks do charge a small fee), is quietest during the winter. If you visit during this time, expect wet conditions—it’s the rainiest time of year. This is also when the park has the least upkeep, meaning watch out for the potholes. The Lady Bird Johnson Grove Nature Trail, near the Kuchel Visitor Center, is popular thanks to its level path and pretty scenery.