Minnesota is seeing a surge in motorcycle deaths this year -- including five riders killed in the past seven days.

The most recent fatality occurred Wednesday at about 8:30 p.m., when a motorcyclist hit a slow-moving farm tractor on southbound Hwy. 10, about halfway between Sauk Rapids and Rice, according to the State Patrol. John R. Mihlbauer, 45, of St. Cloud, died at the scene. He wasn't wearing a helmet.

Mihlbauer was the eighth motorcycle rider to die this month and the 47th to die this year. With more than three months left in 2012, the number of fatalities this year already has surpassed the 42 fatalities for all of last year. August was the deadliest month, when 10 riders were killed.

"This spike in rider deaths reflects how preventable mistakes and lack of attention can wipe out a life and rip families apart," said Bill Shaffer of the Department of Public Safety (DPS) Motorcycle Safety Center. "It's been a violent year on the road for motorcyclists, and it's up to both riders and drivers to reduce these tragedies."

Year in and year out, factors in motorcycle deaths tend to be rider error, alcohol use and motorists' failure to yield, the DPS said.

According to state statistics, motorcycle ridership is at record-high levels with more than 230,000 registered motorcycles and nearly 400,000 licensed operators. Public safety officials urged all riders to take advantage of state programs to hone their skills and reduce the number of fatal accidents.

Funded by a portion of motorcycle license fees, the Motorcycle Safety Center conducts safety education, testing and licensing programs, including rider training classes at 31 Minnesota State Colleges and Universities campuses.

The number of motorcycle fatalities has fluctuated over the years, setting a record in 1980 when 121 riders died. In 2002, 47 motorcyclists died compared with a 24-year-record high of 72 in 2008.

Public safety officials say this year's rise in fatalities could be the result of having more riders on the roads as well as a warm spring that enticed them out earlier. The first motorcycle death was in March.

As autumn approaches, motorcyclists will need to also watch for deer. Public safety officials advise motorcyclists to avoid riding at dusk. For those who encounter a deer, public officials advise stopping quickly. "If impact seems imminent, release the brakes just prior to impact and try to swerve around the deer," officials said. Deer-motorcycle crashes resulted in five of last year's 42 deaths.

Paul Walsh • 612-673-4482