Brooks Range Extremes: -75°F Winters, 90°F Summers

Precipitation stays light, but winds often blow hard and the weather can turn quickly.

Winters are long and severe. Snow falls in eight or nine months of the year, and the central Brooks Range averages 60 to 80 inches. Temperatures of minus 50 degrees or colder are possible, and ice crossings and avalanche conditions add risk, so gear must be properly rated. The long dark months also offer the best chance to see the aurora borealis, or northern lights, from November through March.

Summers are short and cool, yet the sun stays up for at least 30 days straight, with long daylight stretching for months on either side. Backpacking and hiking run from mid-June through September, while float trips are best in July and August. Thunderstorms are common in June and July, and freezing temperatures can arrive at any time, especially from mid-August. Bring insect protection, which is a must all summer.

Getting around means relying on your own feet, a raft, or a small aircraft, since the wilderness has no maintained routes. Many people fly in, while others walk in from the Dalton Highway, which runs roughly five miles east of the park. Once inside, visitors backpack, hike, pack-raft, or simply take in the views. Hikers often head for the Arrigetch Peaks and Mount Igikpak, two of the park's most visited mountains.

Rivers can rise sharply after one rainstorm, and since most trips require crossing streams, shifting weather can alter routes and pickup plans. Glaciers and snowfields are shrinking as temperatures climb, having lost about 13 square kilometers over roughly three decades. Thawing permafrost is also leaving bare soil open to erosion and crumbling hillsides.