NEWARK, N.J. — Summer has not been kind to NJ Transit train passengers.

There were 12 incidents in July that led to major service disruptions. There were only three in July 2009.

NJ Transit spokesman Dan Stessel says 7.6 percent of NJ Transit trains were late six or more minutes last month. That’s the worst record since December 2007. Just 5.7 percent of trains were late in July 2009.

Problems have included overheated locomotives and overhead wires. There also were four deaths on the tracks within nine days in late July and early August.

A 70-foot tree fell in Hamilton last week, causing Amtrak signal problems that closed the Northeast Corridor Line between Princeton Junction and Trenton during the morning rush.