A study of the physics of baseball has shown that air density plays a significant role in the distance a batted baseball will travel. Air density is a function of altitude, temperature, humidity, and barometric pressure. This paper tests if air density impacts the totals market in Major League Baseball by influencing the number of runs in a game above and beyond the betting market total. Through regression analysis and betting simulations of the 2012 season, it is shown that air density has an inverse relationship with total runs scored and simple betting strategies are constructed that yield positive returns.