AP Photo/David J. Phillip

Rescue boats float on a flooded street as people are evacuated from rising floodwaters brought on by Tropical Storm Harvey on Aug. 28, 2017, in Houston. The storm, which later became a hurricane, dumped record rainfall throughout the Houston area. There were six major Atlantic hurricanes in 2017; the average is 2.7. A pair of recent studies found fingerprints of man-made global warming were all over the torrential rains from Harvey that flooded Houston.