That's when sharks are most active, shark attack risk highest in October

In the waters around Hawaii, in the United States, about 20 percent of shark attacks on humans occur in October, according to researchers at the University of Hawaii who analyzed 30 years of statistics. That's far more than any other month of the year.

Tiger sharks account for 63 percent of the incidents, and the study links the increase to their reproductive cycle. When pups are born in the fall, the females are close to shore, exhausted and desperate for food. That means around October in the Northern Hemisphere and around March in the Southern Hemisphere.

The researchers hope the results will help people be aware but not afraid.

"The increase in October is real, but the overall risk is still very low," said Professor Carl G. Meyer, who led the study, in a comment.