The temperature at kickoff was 79 degrees. The sun beamed through large, fluffy clouds hanging over Mercedes-Benz Stadium, 

A perfect day for the Atlanta Falcons to play outdoors.

If only the roof worked.

The new $1.5 billion stadium was supposed to be open for days like Sunday, but officials haven't been able to sort out issues with the camera lens-like structure. 

So, the retractable roof will remain closed for the rest of the Falcons' season, as well as college football's national championship game in January.

(Paul Abell via AP)

"It was supposed to be part of the fan experience," said Falcons booster Calvin Newsome, who was hanging in an area outside the stadium _ savoring the warm weather _ during halftime of Sunday's game against the Miami Dolphins. "But we don't get that because they can't get the roof open."

Actually, the roof does open and close, but bugs in the system mean the process can't be carried out quick enough if inclement weather moves in.

The only Falcons' game played with the roof open was the home opener against the Green Bay Packers, but the fans didn't get to truly savor the moment. The game was played at night.

"When you looked up, it was just black up there," Newsome said.  "You couldn't tell it was open."

(Tom Hauck via AP)

The roof will be open for only one more game this year _ next Sunday, when Major League Soccer's Atlanta United plays its final regular-season match.  

Weather permitting, of course.

As for Falcons fans, they took a double-whammy on Sunday. Not only did they miss out on the unseasonably warm weather, they watched Atlanta squander a 17-point halftime lead and lose to the Dolphins 20-17.

At least when it was over, they could head outside.