Hot weather really does pump up home runs. Here’s how, and why it matters.

Home runs are on the rise in Major League Baseball, as they often are amid warmer summer weather before the all-star break, which starts Monday as the league’s best players head to Seattle for Tuesday’s All-Star Game.

Data makes clear that more home runs are hit when the air is hot and muggy. As the relationship between baseball and weather has become more closely scrutinized and better understood, bettors and fantasy sports enthusiasts now have access to more advanced analytics to guide their strategies.