February temperatures in Fairbanks, Alaska, top out around 8 degrees Fahrenheit, and nights last, oh, 15 hours. But this year, there's reason to consider a Gore-Tex-equipped trip north: because of cyclical solar activity, the aurora borealis should be the strongest it's been in a decade. And the clear, dark sky is the perfect place to watch the most spectacular show on Earth. Make for Chena Hot Springs Resort (from $189), 60 miles northeast of the city, where natural mineral pools reach a steamy 106 degrees. By day, cross-country ski along the resort's 10 miles of birch-and-spruce-lined trails.