Era of hotter temperatures could cause a jump in baseball home runs

According to researchers, if temperatures continue to rise into 2100, there could be a ten percent increase in home runs. The Major League Baseball regular season runs from late March through early October.

Summer is usually synonymous with heat, ice cream and a cool glass of lemonade, but for fans of America’s national pastime, it is also when games warm up and feel the impacts from Mother Nature.

A recently published study by researchers at Dartmouth College suggests a significant correlation between air temperatures and how many Major League Baseball home runs happen each season.

According to the research published in the Bulletin of the American Meteorological Society, more than 500 home runs can be attributed to warmer-than-average temperatures and with the globe continuing to warm, there appears to be no end in sight for the trend.

"There’s a very clear physical mechanism at play in which warmer temperatures reduce the density of air. Baseball is a game of ballistics, and a batted ball is going to fly farther on a warm day," Justin Mankin, an assistant professor of Geography at Dartmouth, stated.

Researchers analyzed more than 100,000 games and took into account performance-enhancing drugs, the construction of bats and balls and other influences on over 220,000 hits.


Only around one percent of hits were attributed to a warming climate, but the study said if trends continue, rising temperatures could account for ten percent or more of home runs by 2100.

"We don’t think temperature is the dominant factor in the increase in home runs—batters are now primed to hit balls at optimal speeds and angles," Christopher Callahan, the lead author, said in a statement. "That said, temperature matters, and we’ve identified its effect. While climate change has been a minor influence so far, this influence will substantially increase by the end of the century if we continue to emit greenhouse gases and temperatures rise."

The weather could fill the position with the tenth man on the field if a team does not have the likes of Babe Ruth, Willie Mays or Hank Aaron to help set records.

Dartmouth researchers believe that the Chicago Cubs could benefit the most from increased warmth due to a limited number of night games at Wrigley Field when temperatures are usually cooler during the summer.

Both Fenway Park and Yankee Stadium fall in the middle of the pack, but teams with indoor facilities, such as the Tampa Bay Rays, do not experience any appreciable increase due to the usually comfortable indoor temperatures.


Readings on the thermometer are not the potential impacts from Mother Nature - teams constantly monitor wind, humidity, precipitation and other factors that can impact a game.

Less than half of the MLB’s 30 teams play in facilities that can be completely sheltered from the weather.