No one knows for sure what causes the Catatumbo Lightning. Some scientists think it's caused by increased amounts of methane gas around the area. Others believe the lightning occurs because of the area's unique location—the very hot, humid air from the Catatumbo River and Lake Maracaibo meets cool air that comes down from the Andes mountains. 9 The mystery of what causes the lightning deepened when, beginning in January 2010, the lightning did not appear for a period of several months. During this time Venezuela, like many other parts of the world, was experiencing abnormal weather patterns, and the country was suffering from a severe drought. Some scientists speculate that this may have caused the Catatumbo Lightning to stop, but the answer remains unclear. Whatever the cause, the lightning resumed that April. main idea