Brevard County Ocean Rescue said stings by the ping-pong ball-sized creatures were particularly prevalent in Cocoa Beach and Cape Canaveral, the Orlando Sentinel reported Monday.
Determined vacationers were taking to the water despite the presence of the red and purple-colored jellyfish.
"Some are braving it," Eisen Witcher of BCOR said. "We're not telling anyone to not go in the water."
Relatively calm waters and an onshore breeze have brought large numbers of the jellyfish toward the beaches, he said.
Most stings have occurred in ankle-deep water, Witcher said, and are typically treated at the beach with vinegar.
How long the creatures will remain in the area is uncertain.
"It's all up to the ocean currents," Witcher said.