From Acadia and Arches to Yellowstone and Yosemite, October is the month we’ve recommended most often. That sweet spot between high and low season, the so-called ‘shoulder season’ is many savvy travelers’ favorite time to be on the road and exploring the great outdoors. It’s the best of both worlds: The crowds are more manageable, as kids are back in school after summer holidays and before ski season, and the weather is less intense, especially in desert regions, where temperatures have usually dropped, and in mountainous areas, where winter hasn’t kicked in completely. You might even luck into some unseasonably warm, gloriously sunny days, depending on where you’re headed. October is also rutting season for many of the large mammals of North America, including elk, moose, antelope and bison, so it's a great time to see wildlife – dramatic mating behavior in particular. Northern exposure: Canada at its best, Given its position north of the 49th parallel, Canada and its national parks are on a slightly different timetable. As a general rule, low season – November to April – is best for snowy-weather sports, shoulder season – May, September and October – has the lowest prices and the most colorful foliage, and high season – June to August – is ideal for hiking in the mountains. The best time to visit a national park? It's right now.