Jackson is jumping in the lake to make good on a bet after the team went 0-16.
Cleveland 19 meteorologist Jason Nicholas said the surface temperature of Lake Erie was in the low 60s for Jackson's Lake Erie jump.
The Browns coach is raising money from the jump.
He will donate $100 toward his foundation that combats human trafficking across Northeast Ohio for every Browns employee that jumps in with him.
The Browns said more around 100 employees jumped in.