It's all for a good cause! Each plunger raised $50 for the Special Olympics. Kennewick Police was a major donor - and say the event keeps growing every year.
The department says they are the biggest fund-raising police unit in the state.
"Feeling very cold, a little anxious, it'll be the one and only time! One of our managers has a child that is part of the Special Olympics. And we did this as a fundraiser for Special Olympics, including their own children," said plunger Randy Posey.
Plungers were extra brave to jump in - considering temperatures were expected to reach the lower 30's - and that was just the daytime high.