Donnlass
I am assuming that the weather wasn't an issue yesterday so unlikely to be due to sudden gusts of wind or windshear alerts.
This would leave the most common reason as the aircraft in front being slow to clear the runway.
Other than that it could have been some kind of technical problem (such as gear not locked properly) showing up on the flight deck displays just prior to the landing or even something as trivial as the cabin not being secure for landing.