There's something about the cold weather — and Atlantic City — that seems to work for Human Nature. The Australian vocal group made its U.S. performance debut here in 2008 with an extended two-month run in the winter.

“It was a great test to see if a U.S. audience would be into what we were doing — four guys from Australia performing a show that celebrates the music and artists of Motown,” recalls Andrew Tierney, who returns with the group on Friday, Jan. 3, and Saturday, Jan. 4, at the Borgata Hotel Casino & Spa in Atlantic City.

“It was a tough two months in the dead of winter, but we knew by the end of the run that we had the confidence to really bring our career to the U.S.”

The A.C. gig led to Human Nature landing a long-term engagement in Las Vegas, where the group recently signed an extended deal with the Venetian.

The group has also forged a creative partnership with legendary Motown singer-songwriter-producer Smokey Robinson.

The latter “has helped us in an incredible way by endorsing our show and he occasionally gives advice for our performances, but for the most part he lets us be ourselves and just stays a fan of what we do,” Tierney says by email from Australia, where the group was in the midst of a holiday season tour.

What Human Nature does is to walk a careful line between honoring the Motown legacy and updating the sound, according to member Phil Burton.

“We always wanted to approach the Motown catalog knowing that these songs were already brilliant,” Burton says by email. “We didn't want our take on them to be vastly different to the originals, while at the same time putting our own stamp on them.

“We like to think our version is what the originals would have sounded like had they been recorded today instead of 50 years ago. I think it's a great fit for us because we have loved this music since we started 24 years ago, and we are now at the point where we have enough experience to perform them the way they are meant to be performed.”

Human Nature also adds a personal touch by weaving in the story of the group, which launched as The 4 Trax while the foursome attended high school in Sydney, Australia. The group changed its name ahead of its 1996 major label debut on Sony, and has since made eight records, including last year's “The Christmas Album.”

“We just perform the songs as if they were our own,” Tierney says of its personal Motown sound. “We also tell our story as a group, so people know that it's real and it's still the same four guys who dreamed of being a vocal group together at high school and are now still living the dream.”

Although individual Motown songs are part of the pop catalog in their native country, the music is not necessarily recognized as being part of a collective “sound.”

“Motown was well-known in Australia, but not nearly as iconic as it is in the States,” Tierney says. “People know all the songs but most likely would not have known they all came from this one record label Motown. I guess we are surprised and proud that this music has become successful for us.

“It's amazing music that stands on it’s own, but its always cool when someone can rediscover such a legacy through a new voice, and we are proud ambassadors to keep the Motown sound alive.”

Early in its career, Human Nature got to tour with another Motown legend — Michael Jackson — and see first-hand what it takes to command an arena.

“It was such an incredible learning experience,” Burton says of appearing on Jackson's “HIStory” tour in 1996 and 1997. “We were his support act for 45 shows, and we got to perform to as many as 100,000 people a night. It was right around the time of our debut album release in Australia, and just before our first tour, so the chance to really study such a great entertainer night after night was the best lesson we could have received.”

For anyone who saw Human Nature the first time around in A.C., you can be sure the quartet has further advanced its “studies” during its time in America.

“We have a bigger production, a great band and we are also a lot more seasoned,” Burton says.