Climate Change Boosts Home Run Rates Across Major League Baseball

Got story updates? Submit your updates here. ›

As the climate continues to warm, the physics of baseball are shifting, with warmer and more humid air leading to increased home run rates across Major League Baseball. A new study found that from 2010 to 2019, an average of 58 additional home runs were hit each year solely due to the warming climate, representing about 1% of all home runs during that period. This trend is expected to grow, with teams in hotter cities like Phoenix potentially seeing an even greater impact.

Why it matters

The changing climate is having a measurable effect on the sport of baseball, influencing factors like ball trajectory and player strategy. As temperatures rise and humidity increases, teams may need to adjust their pitching approaches, defensive positioning, and even ballpark design to account for the increased distance the ball can travel.

The details

The key factor is air density - warmer, more humid air is less dense, meaning fewer air molecules for the baseball to collide with as it flies. University of Illinois researchers found that each 1°F increase in temperature adds roughly 0.33 feet to a ball's travel distance. This translates to an estimated 577 additional home runs from 2010 to 2019 across the league, a statistically significant number.

• Since 1970, the 27 cities hosting Major League Baseball teams have warmed by an average of 2.8°F during baseball season.
• From 2010 to 2019, the American Meteorological Society estimated an average of 58 additional home runs were hit each year solely due to the warming climate.

What’s next

Teams may require to adjust their pitching approaches and defensive positioning to account for the increased distance balls travel as a result of climate change.