AZ-3 First Light at the South Rim
The climate at the Grand Canyon is dramatically different from that of Phoenix, and between the rim and the canyon floor there's also a pronounced difference. The South Rim is at 7,000 feet and consequently gets very cold in winter. You can expect snow anytime between November and May, and winter temperatures can be below 0°F (-18°C) at night, with daytime highs in the 20s or 30s (minus single digits to single digits Celsius). Summer temperatures at the rim range from highs in the 80s (20s Celsius) to lows in the 50s (teens Celsius). The North Rim of the canyon, which is slightly higher than the South Rim and stays a bit cooler throughout the year, is open to visitors only from May through October because the access road is not kept cleared of snow in winter.
Read more: http://www.frommers.com/destinations/grandcanyonsouthrim/1930020157.html#ixzz21kQsfcGY