July is generally the peak of the summer in Arizona, with the average high temperatures in the astonishingly high range of 81°F (27.2°C) to 112°F (44.4°C). Nights vary from a cool 51°F (10.6°C) in the Grand Canyon Village in the north to warm 85°F (29.4°C) in Lake Havasu City in the west. Precipitation reaches up to 4" (102mm) in Bisbee, Green Valley, and Coronado National Monument in the south, with frequent thunderstorms that bring the majority of the rainfall. Temperatures reach above 120°F (48.9°C) in the southern desert region, with 11 hours of intense sunshine in Yuma. Sunscreen is mandatory during most of the day, but it is prudent to avoid outdoor excursions, especially in desert areas where water availability is questionable. Light summer clothing is the best wear, but be sure to carry broad-brimmed hats and sunglasses when out in the open. Severe thunderstorms bring heavy rainfall and flash floods without giving much time to get out of their way. Watch out for thunderstorms during the afternoons in Arizona in July.