"I walked through Trafalgar Square on a Saturday afternoon -- tourist haven -- in pajamas," the multi-Grammy winner told NBC's Matt Lauer in the upcoming "Adele Live in London" special.
"I'm always in black," she added. "It was this tracksuit, with a massive green coat and little pink pumps. I had this massive umbrella so no one recognized me."
Adele said a few passersby did a double-take, though no one approached her, People reported Saturday.
"A couple looked around, but they were like, 'No … she's in color and what would she be doing walking around a packed Trafalgar Square on Saturday in pajamas?'" she joked.
The special is scheduled to air on NBC at 8 p.m., June 5.