Following a three-game sweep by the Los Angeles Dodgers at Coors Field this week, the Rockies sank to 18-28 and fifth place behind the NL West leaders.
They were outscored by a combined 31-13 in LA's sweep.
"As a member of our organization for 16 years, the last seven as our Major League manager, Clint's character, integrity and knowledge has had a tremendous impact not only on our organization but our entire community," Rockies General Manager Dan O'Dowd said in a statement.
Hurdle had a 534-625 record in seven-plus seasons with the Rockies.
Bench coach Jim Tracy -- who formerly managed the Dodgers and the Pittsburgh Pirates -- was named to succeed Hurdle. Tom Reynolds, manager of Colorado's Triple-A minor league affiliate at Colorado Springs in the Pacific Coast League, inherits Tracy's former job.