Luke Bryan isn't having a lot of luck so far with his seventh annual Farm Tour. The country superstar has been forced to cancel another date due to severe weather.

Bryan kicked off the tour Sept. 30 in Ft. Wayne, Ind. The trek is scheduled to run through Oct. 10 before finishing up in Valdosta, Ga. The singer reluctantly re-scheduled a date slated for Thursday (Oct. 1) in Lexington, Ky., due to terrible rains, and on Friday (Oct. 2) he shared the unfortunate news via Twitter that Friday's show in Knoxville, Tenn., has also been postponed, for the same reason.

"I know you guys are mad," Bryan writes. "I am heartbroken. We schedule farm tour in October because it is historically the driest month of the year."

"Atvs were bogging up," he adds. "I will play in the rain but I can't strand you guys in your vehicles for days."

The "Strip It Down" singer apologized profusely in a series of further tweets:

The Lexington date has been re-scheduled for Oct. 6, while the show in Knoxville will be re-scheduled for a date yet to be determined.

Bryan's 2014 Farm Tour played to more than 110,000 fans. 2015 is slated to be even bigger — if the weather will cooperate — with Sam HuntChris Janson, the Peach Pickers, Chancie Neal and DJ Rock all joining him for the shows. A portion of the ticket proceeds will be donated to the Luke Bryan Farm Tour Scholarship fund, which helps provide college scholarships to students from farming families in local communities the tour visits.

See Luke Bryan's Sexiest Pics