Summer clouds forming over Mather Point, Grand Canyon National Park. NPS Photo by W.Tyson Joye.

Mather Point, a short walk from the Visitor Center, parking lots and the shuttle bus transit station, is one of the most popular and busiest viewpoints on the South Rim of Grand Canyon. For visitors entering the park on the South Rim, Mather Point is the often the first place to stop and view the canyon.

From Mather Point, the views are spectacular and there are many places to look down into and across the canyon.

Summer storms in the southwest are often accompanied by potentially deadly lightning. Visitors walking and hiking in the park are reminded that if they can hear thunder, they should consider ending outdoor activities.

If the sound of thunder follows a lightning flash within 30 seconds, seek shelter inside a building or vehicle. If this is not possible, move well away from high points such as ridges and the edge of the canyon. Do not seek shelter beneath tall trees. Lightning strikes within Grand Canyon National Park an average of 26,073 times per year.

For more on how to be "lightning smart" download the Grand Canyon Lightning Danger Info Sheet: <a href="http://www.nps.gov/grca/planyourvisit/upload/LightningDanger.pdf" rel="nofollow">www.nps.gov/grca/planyourvisit/upload/LightningDanger.pdf</a>

Summer temperatures on the South Rim, at 7000 feet (2135 m), are relatively pleasant with high temperatures generally in the 80s (27-32°C) (with temperatures typically warming to over 100 degrees (>38°C) at the river near Phantom Ranch (2400 feet/762m). North Rim summer high temperatures are typically cooler than the South Rim due to increased elevation (8000 feet/2440 m), with highs typically ranging in the 70s (21-26°C).

Overnight lows can still drop near to below freezing occasionally on the North Rim, although typically low temperatures range from the 40s and 50s (4-15°C) at the South Rim to the 60s and 70s (16-26°C) at Phantom Ranch.