Foul weather is forcing the cancellation of the final day of one of the nation’s biggest agricultural exhibitions, what’s considered the World’s Fair of everything farm-related.

Dena Morgan, spokeswoman for the Farm Progress Show in Boone, says it’s a huge disappointment, but the show will not go on today and it’s now closed for the year. “We’re not going to open,” Morgan says. “It was raining this morning and it was forecast that there was lightning coming through, so we decided to close the show for everyone’s safety.”

The show opened Tuesday. Organizers have 600 vendors on the grounds and had been expecting up to 150,000 visitors over the three-day run.