Visitors to Glen Canyon National Recreation Area (NRA) may be surprised to learn just how dry the Colorado Plateau region is. The central Colorado Plateau region, which includes Lake Powell and surrounding land, is in a rain shadow, or region of reduced rainfall caused by the protection of mountains to the east and west. Page, Arizona, located near the Glen Canyon Dam, only receives 6.46 inches of rain annually, which is less than Phoenix situated in the Sonoran Desert. Precipitation is bimodal, with a late summer – early fall peak and a late winter peak. Between November and May, storms move into the area from the Pacific Ocean. During Arizona's monsoon from July to September, storms move northwest out of Mexico. Although most precipitation is in the form of rain, winter storms occasionally bring snow, especially at higher elevations in the area. The driest month is June, and the wettest is typically October. Average monthly temperatures vary from around freezing in the winter to 75°F in July. The record high for Page is 109°F, recorded on July 5, 1985. However, humidity is typically very low in the region, and thus hot days are not as uncomfortable as they can be in more humid regions.