Is the new Yankee Stadium indoors?

No, but more and more are now. 6 out of 12 (although teams don't play all their home games at the main home stadium). Teams with domed stadiums: Fukuoka Softbank Hawks (retractable roof that is never retracted during games) Orix Kintetsu Buffaloes Nagayo Chunichi Dragons Tokyo Yomiuri Giants (inflated like the Metrodome) Hokkaido Nippon Ham Fighters Seibu Lions (but there is a big umbrella, open all the way around the edges so no climate control.) (more being built in the future)