PHOENIX — For the first time, Major League Baseball is standardizing how its 30 clubs store baseballs, according to several sources familiar with the plan distributed to clubs. Baseballs must be stored in “an air conditioned and enclosed room” this season.
Major League Baseball will install climate sensors in each room to measure temperature and humidity throughout the 2018 season. That data will be used to determine whether a humidor is necessary in individual storage rooms for the 2019 season.
The Arizona Diamondbacks are installing a humidor this season. Their room is designed to store baseballs at the MLB recommendations of 70 degrees and 50% humidity.