YARMOUTH — A spokesman for the Yarmouth Clam Festival said Sunday night that intense 90-plus-degree heat on Friday and the threat of severe thunderstorms on Saturday discouraged people from attending the three-day celebration.

Ben McNaboe, the festival’s assistant director, said the clam festival historically has attracted between 100,000 and 140,000 people. But he said organizers estimate the 48th annual clam festival saw a 30 percent dropoff in attendance.

“It was the heat on Friday and then the threat of thunderstorms on Saturday. But it never rained once,” he said.

The Friday night parade is usually well attended, but McNaboe said, “the parade crowd was a little thinner than usual.” Temperatures reached into the mid-90s that day, making it the hottest day of the year. 

McNaboe said Sunday’s sunny, mild weather drew huge crowds, however.

McMaboe said the traditional diaper derby, which was held Sunday, attracted more entries than usual. The clam festival officially ended Sunday around 5 p.m. with live performances by Amy Allen and the Jerks of Grass band.

The festival is sponsored by the Yarmouth Chamber of Commerce.