Most likely the radio is broken.
Water and electricity don't go together.
〉 Answered on Sep 4th, 2013 by Amy Mattinat, Owner and Author at Auto Craftsmen Ltd
You may be able to seek out a radio head replacement at your local salvage yard. The moisture very well may have damaged the contacts on the inside of your radio.
〉 Answered on Sep 4th, 2013 by Amanda J. Pierce, MBA "AJ", Certified Mechanic, Project Coordinator; Primavera Scheduler at VIGOR Alaska Industrial Shipyard & BizzM3ch Solutions
Start with checking the fuse for the radio. On some vehicles the clock and the radio itself are on seperate circuits. If the fuse is good, I would recommend taking it to a repair shop to have the radio removed and checked for further damage.
〉 Answered on Sep 4th, 2013 by Helaine Kurot, Owner/Technician at 360 Automotive
Unfortunately not much. You can wait and see if it dries and then starts working, but you may need to replace the radio. Good luck.
〉 Answered on Sep 4th, 2013 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines