But for Ehsan Ahmadi and his nephew Muhamed, this is no ordinary day, and theirs is no ordinary hello. The pair haven't seen each other in almost a decade.
Muhamed is just 14 years old, yet he has spent more than a year trying to get here, risking his life more than once on the perilous solo trip from Afghanistan to Europe.
"It was very difficult," he tells CNN. "I passed 12, 13 countries to arrive here, the last one was France, and now I'm finally here."
They can't conceal their joy at being reunited after so long, amid the tour groups and business travelers flowing through the arrivals hall.
"I'm very happy," says Muhamed, who is carrying everything he owns in a small, gray, wheeled suitcase. "I'm so happy to come to the UK and join my uncle."
"I'm glad too," Ahmadi says, with a beaming smile.
The last time they met, when Ahmadi returned to Afghanistan briefly to get married, Muhamed was a little boy who held his uncle's hand. Now he's a fashionably-dressed teenager, as tall as his uncle.
Perilous journey alone
CNN first met Muhamed in the "Jungle" in Calais, just before the camp was torn down in October. He was one of the thousands of unaccompanied minors living there, desperate to reach the UK. Muhamed's brothers, sisters and parents still live in Afghanistan.
When the Jungle was demolished, like hundreds of others, he was left in limbo, transferred to a reception unit
in central France while Britain's Home Office assessed his case.
And now, after so much waiting, he's made it: Heathrow is the last stop on his long journey to his uncle's family in Rotherham, northern England.
Ahmadi, 35, a builder, says he has been "living as a guest" for 15 years in the UK, where he has indefinite leave to remain. "I like it here," he says. "My country has problems."
He left Afghanistan's Panjshir Valley in 2001, following a similar route to the one later taken by his nephew -- though he says he didn't make the "very dangerous" Aegean Sea crossing from Turkey to Greece, and was horrified to hear Muhamed had traveled that way.
Asked if he still longs for the place he was born and grew up in, he says: "Home is family and friends. What you miss is people, not geography."
Exciting plans for the future
Ahmadi says he, his wife, Nasrin, and their five children, aged one to eight, have been looking forward to Muhamed's arrival for months.
He says it will be crowded at first in the family's two-bedroom house, but they are planning to move to a bigger place soon.
His oldest son is "very excited," Ahmadi says -- he can't wait to have a big brother to play football with, and take him to the local sports center.
"I will be pleased to meet them," says Muhamed, adding that he's looking forward to joining the local school and meeting new people.
"I came here for continuing my education, and I love football, playing football," he says. "I want to meet some more [people] for making friends."
Muhamed's enthusiasm for his new home is undimmed even by the gray skies that greeted his arrival -- the famous British weather.
"It's very good," he insists. "Better than France. If the weather is very cold, I am very warm because I joined my uncle. I don't feel any cold here now."
Memories of the past
But amid all the excitement of their long-awaited reunion, there is sorrow too.
While most would say that Muhamed's ordeal has a happy ending, his uncle isn't so sure: "It's a sad story for people to have to leave their home, to be refugees. It shouldn't happen anywhere."
A spokeswoman for the UK Home Office declined to reveal how many unaccompanied minors had been brought to Britain from Calais.
The Home Secretary told Parliament recently that more than 300 minors have been transferred to the UK so far, and that several hundred more will be moved across in the coming weeks and months.
Muhamed is among the lucky ones.
"Some [of my] friends from the center have come to the UK today, but I'm 50% happy, 50% sad, because some of my friends are still there," he says.
Muhamed's memories of the loved ones he has left behind, and of his experiences on the road and in the Jungle, will linger long after he has settled in to his new home.