when do they close the roof at safeco field
Safeco Field Safeco Field has a unique retractable roof that only acts as an "umbrella" for the stands and field rather than forming a complete climate-controlled enclosure, as is the case with all other retractable roofs in Major League Baseball. Seattle's relatively mild climate means the park rarely needs to be heated or cooled, but frequent precipitation necessitated a roof. The roof is sometimes closed, however, in dry weather when the temperature is particularly low. On cold nights, closing the roof helps prevent radiation heat loss. The only other covered baseball stadium in the world with permanent openings is the fixed-roof Seibu Dome in Tokorozawa, Saitama, Japan, home of the Saitama Seibu Lions.