June to August is driest; April, May, September and October are the honest compromise; February is closed. The catch is permits: the best months sell out within days of the November release.
Shoulder. Mostly dry, greener and a little quieter. April and May sell out within one to three days of the November release.
The classic trail has two seasons and one closed month. The dry season runs from April to October, with the driest and clearest weather from June to August; the wet season runs from November to March, and the whole trail closes every February for maintenance. Climate averages for Cusco give one to three days with rain in June and July, and 19 to 21 in January — the cloud forest on day three is wetter than the city.
The best chance of a clear sunrise at the Sun Gate, cold nights at the high camps, and the hardest permits to get: June and July dates sell out within 24–48 hours of the November release. If these are your months, book five to six months ahead and treat the date as fixed.
Mostly dry, greener and a little quieter. April and May sell out within one to three days of release. Two to seven days with rain in May, five to ten in September, and more in April and October as the seasons turn. The partner calendar below shows which dates are still open.
Afternoon rain and cloud on the passes, slippery steps on day three and fewer views — but permits stay open longer. Thirteen to seventeen days with rain in November, sixteen to twenty in December and thirteen to twenty in March. Pack a proper rain shell, not only a poncho.
Permits for a calendar year go on sale in November of the year before, month by month over about a week. For May to September, book five to six months ahead; for the rainy months there is usually more time, but no published figure says how much. If your month is gone, the 2-day Short Inca Trail uses a separate permit pool that often stays open two to three months out.
In the dry months the day-two climb starts cold and ends warm — one listing gives 3–20 °C on the day of the pass — and nights at the high camps are the coldest of the year. In the wet months the passes are often in cloud, the stone steps of day three are slippery, and a rain shell matters more than a warm layer. Neither season changes the route, the distance or the permit rules.
February is closed. No operator can sell a February date on the classic trail, and the 2-day Short Inca Trail from Km 104 closes with it. Any listing that shows a February date is selling a different route — treks such as Salkantay need no Inca Trail permit and run all year.
Pick the month, then the trek. The season decides the weather; the permit decides whether you go at all. Check the partner calendar for your month before you plan flights around it, and see which of the three treks below fits your group.