This Sunday marks another sign of spring — the beginning of the Major League Baseball season. It is a time of renewal and promise, with every team’s record unblemished and full of hope before the season heats up. This week, we look at baseball season temperatures changes, both within the season and how seasons overall have changed.
From first pitch, temperatures rise through the season until a summer peak before falling as the World Series approaches. The swing in temperatures varies across the country from a maximum of 34 degrees in Minneapolis and Toronto to only 9 degrees in Miami. Also, temperatures peak at different times of year for different locations — as early as June in the Southwest to the 4th of July weekend across the Great Lakes to as late as September across the West Coast. We ranked which teams have the largest temperature ranges and highlighted each team’s temperature curve in the cities where they play.
But there is also the longer term warming that has occurred due to the increase in greenhouse gases from the burning of fossil fuels. We analyzed the temperatures during the Major League Baseball season and found that during the months of April through September, the national average temperature has risen 1.08°F since 1895.
Globally, 2015 was the hottest year on record and this year is on pace to be even hotter than last year. The warming trend is clear, as the last 7 calendar seasons have been their hottest on record, and the 16 hottest years on record have all been since 1998. Looking to the future, fastball pitchers will not be the only ones bringing the heat, as the months of the baseball season will warm further in coming decades. Visit our interactive, Danger Days, to see how heat and humidity will increase the number of days where heat-related illnesses become a threat.