[caption id=“attachment_12108” align=“alignnone” width=“750”]NBC's Al Roker headlined the "Today"/USO Comedy Tour in Afghanistan last month. USO photo by Fred Greaves NBC’s Al Roker headlined the “Today”/USO Comedy Tour in Afghanistan last month. USO photo by Fred Greaves[/caption]

USO tours look fun, and they are. But they’re also grinds for the celebrities and crews involved in flying across the world and putting on the shows for America’s deserving service members.

Al Roker experienced one of those whirlwind tours last month, when he headlined the “Today”/USO Comedy Tour’s one-day, multi-show effort at Bagram Airfield, Afghanistan. Now, he’s right back at it, hosting what NBC is dubbing Rokerthon: his effort to set the Guinness World Record for longest continuous weather report while also raising funds for the USO.

“The idea that you can put a smile on [the faces of troops] … that’s why you’re doing it,“ Roker said of his October USO tour to Afghanistan. "Their face lights up. And you’re like ‘wow, I am making a difference for these people.’”

Roker kicks off his effort tonight at 10 p.m. on today.com and will attempt to stay on the air across NBC’s different platforms reporting about weather until 8 a.m. Friday. If he does it, his 34-hour stint will break the current record of 33 hours by a Norwegian meteorologist in September.

As a central part of his record-breaking effort, Roker is asking people to contribute to his Crowdrise page, which is raising funds for the USO.

According to Today’s website, you can participate via social media by sending weather questions, photos and lines of encouragement to keep Roker going by using #Rokerthon.

(And speaking of world records, the USO set a Guinness mark of its own earlier this year.)