(Adds quotes from governor)
By Steve Olafson
OKLAHOMA CITY, Aug 3 (Reuters) - Wildfires burned out of control on Friday in Oklahoma, destroying homes and shutting down highways in a state that has suffered 18 straight days of 100-plus degree temperatures and persistent drought.
Emergency officials counted 11 different wildfires around the state, with at least 65 homes destroyed in parched areas north and south of Oklahoma City and south of Tulsa.
Oklahoma joins several states that have been plagued by wildfires this summer, including Colorado, Arkansas and Nebraska. Fires are being fed by a widespread drought.
Nearly two-thirds of the contiguous United States was under some level of drought as of July 31, according to the Drought Monitor, a weekly report compiled by U.S. climate experts.
Interstate 44, historic Route 66 and state highways were closed, but no deaths were reported in the Oklahoma fires.
Low humidity, strong southerly winds and drought conditions enabled the wildfires to spread quickly across treetops, said Michelann Ooten, deputy director of the state's Office of Emergency Management.
"It's just a very difficult situation we're facing that's all weather related," Ooten said.
Governor Mary Fallin, who earlier in the day invoked a statewide ban on outdoor burning after declaring a state of emergency for the state's 77 counties, told Reuters fire conditions may be worse on Saturday.
"The fire danger might be even higher," she said.
Oklahoma has contacted neighboring states for help, but they are contending with their own wildfire threats and no out-of-state help is on its way, she said.
"There's fires in Arkansas. There's fires in Kansas and Texas. Everybody else is on high heat alert," she said.
The heat in Oklahoma City, the state capital, has reached historic levels.
On Friday, Oklahoma City tied its all-time record for the highest temperature ever recorded when the thermometer reached 113 Fahrenheit (45 Celsius), a mark last recorded in the Dust Bowl days in 1936, according to the National Weather Service in Norman, Oklahoma.
Volunteer fire departments have made a public plea for Gatorade donations to keep their crews hydrated in the scalding conditions. (Reporting by Steve Olafson; Editing by Mary Wisniewski and Lisa Shumaker)