Temperatures in Anchorage aren't much colder than in central New England. Head inland toward Fairbanks and even farther north, and temperatures drop south of zero, where they stay for days at a time. Days in midwinter are short; how short depends on whether you're in Anchorage or north of the Arctic Circle, where the brightest it gets on December 21 is a sort of muted twilight. But after the solstice, the days lengthen quickly, and by late February there is plenty of daylight, even north of the Arctic Circle.

The bottom line: Where and when you travel makes a big difference. Depending on your inclination and tolerance for cold, you can expect a moderate trip—or an extreme one.