U.S. hotels' May average daily rate increased 5 percent year over year to $120.64, according to STR.

Occupancy increased 0.8 percent to 67.5 percent, breaking the historical record for the month, STR senior vice president of strategic development Jan Freitag said. Denver experienced the largest increases in ADR (15 percent to $123.86) and occupancy (6.1 percent to 80.6 percent) among the top 25 markets. Houston reported the largest decreases, as ADR dipped 2.5 percent to $121.40 and occupancy dropped 6 percent to 71.4 percent.