Local police say vehicle burglaries increase about 100 percent between April and October compared to the months between November and March.
Police statistics show, over the past five years, nearly 1,100 vehicles were burglarized in Moline alone.
The number of vehicle burglaries jumps dramatically in April, and remains high through October.
The highest number is reported in July.
Police say most of the break-ins are preventable, because "92.6% were to unlocked cars." Police say prevention is as simple as locking your home, your garage and all vehicles.
Fewer than 7.5% of vehicle break-ins involved a broken window or other forced entry.
"If you're breaking a window, someone may hear you. A police officer may hear you, a car owner may hear yo, you're going to draw attention to yourself. It's very quiet to open a car door and get in that way," said Detective Michael Griffin of the Moline Police Department.
Griffin said that thieves will take car radios, GPS systems, cash, and anything else valuable. He advised people take their valuables inside and not leave anything in plain view inside the car.
Most of Moline's arrests for vehicle burglaries - 96.3% - are males, and their average age is 17 years old.