The Inca Trail is open all year, with the exception of February. During February, the local authorities arrange for trail improvements and campsite restorations.
The best time of year to hike the Inca Trail is during the dry season – generally April 15th to November. The rainy season comes on slowly in November and December and is at its strongest from January through early April. Of course, the flora surrounding the trail and among the ruins themselves will be at its greenest during and just after the rains. So May, June and July are the most popular months as folks take advantage of the combination of drier weather with the greener hillsides.
Of course, Jen and I did the trip in December. We really were quite lucky in doing so. During our ten days in the area, it rained on us only twice. It was cloudier for a few days than it would be in peak season, but we only truly got wet twice (not bad for “rainy season”). And on one of those two days, we ended up at Phuyupatamarca (“cloud level town”) just in time for the rain to stop, the clouds to lift, and the llamas to show us that amazing sunset over Salcantay. Blue-sky days are always great, but a well-timed sunset after the rain… there’s not much better than that!