Air density does have an effect, but the density change from temps that we've seen in the last few years (say a 75 degree game vs an 80 degree game) is only goi

Air density does have an effect, but the density change from temps that we've seen in the last few years (say a 75 degree game vs an 80 degree game) is only going to get you a couple feet of ball travel. While it make a difference on balls that just barely clear the fence, it definitely doesn't account for the entire boom in home runs. For comparison, a ball hit 400 ft at Yankee Stadium (400 ft elevation) would go 440 ft at Coors Field (5280 ft elevation). That's a 10% increase in ball distance for a 17% decrease in density. Increasing the temp by 5 degrees F drops the density by 0.8%, which is probably only good for 1-3 feet. https://chem.libretexts.org/Exemplars_and_Case_Studies/Exemplars/Sports%2C_Physiology_and_Health/Home_Run_Distance_and_Humidity https://chem.libretexts.org/Exemplars_and_Case_Studies/Exemp... https://wahiduddin.net/calc/calc_da.htm https://wahiduddin.net/calc/calc_da.htm