The North Rim is the remote area of the canyon and gets quite a bit of snow in the winter and is only open seasonally (May 15 - October 15). Expect dry, hot temperatures on the West Rim during the summer, so stay appropriately protected from the sun and hydrated to make the most of your visit. This is the rim located closest to Las Vegas, is the warmest year-round, and features the Grand Canyon Skywalk.
The South Rim does get some snow in the winter, which often makes for a very special (and less crowded) time of year to see the Grand Canyon. This is the most popular rim to visit, enjoys moderate temperatures, and can be accessed year-round. Grand Canyon weather varies from rim to rim.