As you can see by the average temps from 2008, Grand Canyon National Park is a place of extremes. You need to be prepared for pretty much any kind of weather - from scorching heat to chilly lows within a matter of hours. The weather inside the canyon itself near the bottom can be very extreme, often hitting 100 degrees. The"shoulder seasons" are especially unpredictable in Grand Canyon National Park. Expect snow and ice in the winter seasons. The South Rim is at 7,000 feet in elevation, while the North Rim is around 8,000 feet. This is not a low elevation park except for the bottom of the canyon which
is 2,800 feet. Always pack a a variety of clothes to meet the possible conditions you may encounter here. Those sticking to one elevation(or rime)and not hiking into the canyon have less to worry about, although there can still be surprises.

Temps:

December: 15 to 64 degrees
April: 13 to 78 degrees
July: 45 to 93 degrees
October: 13 to 78 degrees