While there are several problems that lead to windshield wiper chatter, Popular Science reports one of the most common is a bent wiper blade causing the blades to strike the windshield at something other than a 90 degree angle. It suggests using a couple of adjustable wrenches to bend the arm back to the correct angle.
Dirt, oil and wax on the glass or wiper blade also cause chatter. A good glass cleaner and a good scrub help to remove the buildup to eliminate the problem. Cleaning the glass in this way also gives the vehicle a great shine. Cleaning the wiper blades also helps to ensure they work correctly.
Operating the wipers in below freezing temperatures also causes chattering. The problem is often that there is still a layer of ice on the glass. Drivers overcome this issue by allowing the defroster to heat the glass and melt the ice. A deicing spray helps to speed the process.
While the noise of wiper chatter is annoying, their effects can make driving dangerous. They leave streaks on the windshield, impairing the driver's vision. While cleaning the glass at the service station with a squeegee provides temporary relief, fixing the problem correctly helps to ensure safer travel.