I hate crowds and rain! What is the best time to visit Machu Picchu? April? May? October?

I vote for May.

1. The rainy season has ended.

2. Things are still lush and green since the rainy season has only recently ended.

3. The highest of the high season has not yet kicked in.

The one drawback with May is the fog (the garúa) in Lima, which can delay flights.

Hey Maggie.
I trekked the Inca Trail (you really should do this) in April 2014. Fine fine weather. Minimal crowds. I'm allergic to tourists. HATE crowds. The trail was very light on trekkers. Macchu Picchu was blessedly light on tourists. My kind of timing. Jeff's also right. April May time frame is their October-November. October is a very sweet time to be in Peru. I spent the whole month there, it was heaven. Otherwise it's like Grand Central Station out there. Pick a shoulder month or else you are neck deep in touristas.

All good points. Any thoughts about October/November?

I like September or October as well, but it won't be as green as May. You can get waves of rain in those months, though.

I think May is turning into a very busy month, though.

May through Sept. is the dry season in the Andes. Five years ago, we visited the end of May-mid June for 2 weeks. The weather was perfect-springlike temps and no rain. Because it is the high season, there may be a lot of tourists. However, when we were there 5 years ago, we did not find the sites crowded.

Things have changed a lot in 5 years. The 100th "anniversary" and improved safety has exploded visitor numbers. They now have a capacity limit on the number of visitors per day, but it's far to high to make the site seem "uncrowded".

It's still worth going but don't expect much peace and quiet.

My Peruvian friends told me the best time is early July--after Inti Raymi so you don't have the crowds (and lodging markup) in Cusco and MP, and it will be dry season.