The seventh annual Pooch Plunge at Potterfield Pool will be Wednesday, Sept. 8, from 5:30 to 8:30 p.m.
The pool is at 730 Frederick St. in Hagerstown.
The event will benefit the Humane Society of Washington County.
Last year, 171 dogs and 286 people joined in on the fun.
The City of Hagerstown Parks and Recreation Department provides use of the pool each year for the event.
Last year's event raised $1,117 for the shelter.
Admission to the event for one dog plus one handler costs $5. Additional humans or pets will be admitted for $2 each. For more information, call 301-733-2060, ext. 237.