I've heard May and September/October, justified on the grounds that the trail (and presumably the MP site itself) are too crowded in June and July, there's too much trash, etc. On the other hand, September and October are listed as averaging 21 and 26 days of rain respectively, whereas August averages 12 (May averages 13). Both from the standpoints of photographic conditions and trail slipperiness, it seems like it would be a good idea to avoid months known for frequent rains. As always, I appreciate hearing about what experiences others have had.

I have visited Cusco and the Sv at all times of the year, usually for extended periods over many years and have noticed the changing climate. It is often said that May to September is the "dry season" but as with many places around the world, climate change is blurring those dates somewhat and those dates are no longer as certain as they once were.

I wouldn't pay much heed to sites quoted the number of rainy days as many of those will include just light rain showers. I recall arriving in Cusco one year right at the beginning of May to be greeted by torrential rain which counted for a week. After that nothing but blue skies for the next three months. May is good because the crowds have yet to arrive and the scenery will still be green after the rains. By the time June arrives, so will the crowds and the landscapes start to look a bit brown and arid. It will be much the same until September October. If you want green landscapes, smaller crowds and cheaper hotel rates, late May/June is arguably your best option. Trash clear up is better than it once was but clearly this is going to be less of an issue at the beginning of the season than the end.

The traditional Inca Trail is undoubtedly over touristed but it is but one of lots of treks in the area. Many, including myself, choose to do one or more of the less busy trees - Lares, Ausungate etc and combining that with a trip by train to MP from Ollantaytambo. perhaps even better still, consider heading north to Huaraz and the Cordillera Blanca

It was a long time ago, but I hiked in June 2008. The weather was great. I didn't think the trail was crowded, and I never saw a single piece of trash. We had no rain, but of course, that's never a guarantee.

Unless things have changed, there are capacity limits on how many hikers can be on the trail, so that does help with crowd control. Be sure to apply for your permit well in advance. The guide service can help with that, and you do need a guide service.

Thanks to you both! May of next year is sounding like a very promising time, since I'm very big on photography would love to have deep green in the photos.

You are welcome. May 2027 will provide plenty of time to sort out the logistics but don't leave it too late as traditional Inca Trail passes get booked up well in advance even in non peak season as do train tickets to and from Agauas Caleintes etc.. Do also check out teh credentials and ethics of your trek operator. Some treat their porters and staff pretty badly (despite what they may say in their promo stuff)

I went in late May and it felt like a sweet spot - dry enough for good views but not peak chaos yet. I’d avoid Oct unless you’re okay with hiking in mud half the time - this guide actually help me plan mine: explorerspassage.com/chronicles/top-machu-picchu-hikes.