Humberside Police have put out a warning to youngsters who may be tempted to try river jumping during the warm weather.
Pc Steve Wilson said: “Due to the recent warm weather we have had a lot of kids river jumping, especially on Skerne Road.
“They are not committing an offence but it is quite dangerous and e want to make these young people aware of the dangers they are putting themselves in.”
Police will be patrolling areas where river jumping is prolific.
“We are going to be sending letters to parents to let them know what is going on and the to the dangers of it,” PC Wilson added.