I think if you check he was on his way back from a month long vacation in TX when he stopped over in FL at the school on 9/11.
In early August 2001 he had received a briefing that referenced a possible attack.
August 4-30, 2001: Bush Nearly Sets Record for Longest Presidential Vacation
President Bush spends most of August 2001 at his Crawford, Texas, ranch, nearly setting a record for the longest presidential vacation. While it is billed a “working vacation,” news organizations report that Bush is doing “nothing much” aside from his regular daily intelligence briefings. [ABC News, 8/3/2001; Washington Post, 8/7/2001; Salon, 8/29/2001] One such unusually long briefing at the start of his trip is a warning that bin Laden is planning to attack in the US (see August 6, 2001), but Bush spends the rest of that day fishing. By the end of his trip, Bush has spent 42 percent of his presidency at vacation spots or en route.