David Shaw, Senior Vice President of the American MMA promotion UFC, explained the organization's decision not to host major events in stadiums.
Shaw stated, as quoted by Bloody Elbow:
We don’t want to take the risk of weather. The production costs would be tremendously large if we had to deal with the weather. And then you’ve got the situation risk of having a real negative impact on the field of play.
On August 18, UFC 305 took place, featuring a main event in which middleweight champion Dricus du Plessis from South Africa defeated Nigerian fighter Israel Adesanya.
Du Plessis now boasts a record of 22 wins and two losses, while Adesanya holds a record of 24 wins and four losses.