Dowtown Yuma, Arizona from I-8
Yuma is a city in and the county seat of Yuma County, Arizona, United States. It is located in the southwestern corner of the state, and the population of the city was 93,064 at the 2010 census, up from the 2000 census population of 77,515.
Yuma is the principal city of the Yuma, AZ Metropolitan Statistical Area, which consists of Yuma County. According to the United States Census Bureau, the 2012 estimated population of the Yuma MSA is 200,022, though more than 85,000 retirees make Yuma their winter residence.
Yuma features a subtropical desert climate (Köppen climate classification BWh), with extremely hot summers and warm winters. Humidity is usually low except during what are called "gulf surges", when a moist air mass from the Gulf of California is drawn northward, usually in connection with the summer monsoon or the passage of a tropical storm to the south. Yuma is the hottest city in the United States, with a record average of 175 days per year with a daily maximum temperature of 90 °F (32 °C) or higher. Yuma is also the sunniest place on Earth, according to Guinness World Records. Of the possible 4,456 hours of daylight each year, the sun shines in Yuma for roughly 4,019 hours, or about 90% of the time.
Yuma contains the historical Yuma Territorial Prison, the Yuma Quartermaster Depot State Historic Park (formerly known as the Yuma Crossing Historic Park), and a historic downtown area. Yuma is an Arizona Main Street City.
The city is the location of the Marine Corps Air Station Yuma, which conducts an annual air show and many large-scale military exercises. There is also the Yuma Proving Ground, an Army base which tests new military equipment. Yuma Proving Ground is also home to the Special Operations Free Fall School, which provides training in Free fall parachute operations to Special Forces units in all branches of service, as well as those of other nations.
The Colorado River runs along the north and west side of town, and serves as the border between Arizona and California. Yuma is an important station for trucking industry movement of goods between California, Arizona and Mexico.