Current Weather in Maryland Heights, Missouri View Current Weather Average Temperature and Rainfall in Maryland Heights, Missouri Month Monthly Average Temperature (Fahrenheit) Monthly Average Rainfall (in inches) January 29°F 1.8″ February 34°F 2.1″ March 45°F 3.6″ April 57°F 3.5″ May 66°F 4″ June 75°F 3.7″ July 80°F 3.9″ August 78°F 2.9″ September 70°F 3.1″ October 58°F 2.7″ November 46°F 3.3″ December 34°F 3″