"I think he's mad but he's got balls, " says one shopper. The real Father Christmas hardly gets a look-in - Belfast's Black Santa holds this city's heart.

He doesn't exactly frighten children but they do give him "quizzical looks" when their parents bring them along - particularly the babies in prams, he admits.

But beneath the black cape, cassock and knitted hat, there's nothing to fear. The Rev Houston McKelvey, Dean of the Church of Ireland cathedral, is a nice, normal, but hugely committed man. It's his sixth year as 'Black Santa', a tradition that a predecessor began three decades ago.

When his week-long sit-out ends tonight, McKelvey hopes to have raised £200,000 for charity. "It is cold but people have been wonderful, " he says. "They don't just give money, they try to warm you up.

"Cups of tea and coffee have been sent round from local cafés. There haven't been any mince pies or sherry but there has been plenty of Mars bars and toffees - terrible on the teeth though!"

From 8.45am to 5pm each day, "or later if the money is coming in", McKelvey stands outside the cathedral in Donegall Street with his barrel ready for donations, braving the elements.

"The wind is the worst, " he says. "It blows across Writers' Square, bounces off the front of the cathedral, rolls down and then hits you in the back. It's like a car bomb in reverse.

"Cathedrals, by tradition, are windy places.

Not just because of their physical location, but in the demonic sense. Where God is active, the devil will be too."

But the wind brings advantages: "The colder the weather, the more generous people will be. It appeals to them. There's something peculiarly Celtic about their clergy freezing - it goes back to the penitentiaries."

His rig-out has led to "the caped crusader" nickname. "I'm just waiting to be called Batman!" he jokes. Despite all the layers, there's not a thermal vest or pair of long johns in sight.

"It was too much bother, putting them all on and taking them off again. But I'm a keen sailor and when the weather gets really dirty during the sit-out I put on my oilskins."

Somebody sent round a patio heater: "It was as much use in Donegall Street as it would be at the South Pole!" Not that he's complaining. "The sit-out is about more than fundraising. The rich tapestry of human life is here.

"You see all sorts: people arriving at the cathedral in top-of-the-range 4x4s, others on bicycles; people in designer labels, others in the duff stuff. We've had grannies emptying their purses of change, teenagers bringing their pocket money and one of the city's leading stockbrokers donating £6,000."

There's a pastoral aspect too. "People with a range of social problems come to chat, " McKelvey says. "Christmas is a lonely time for many who feel they are outside looking in.

A lovely lady yesterday told me about her husband's death. I take confessions at the barrel. You are like Moses, you are standing on the holy ground."

There is humour too: "A man asked for support for his son who was in hospital with an alcohol problem. Then he handed me a 10glass bottle of whiskey. I thought, 'If I drink this, I'll be in the bed beside the young lad!'" Although the sit-out takes place at the Church of Ireland cathedral, it is "owned by the whole community, and not just the Christian community", the dean stresses.

Belfast's SDLP lord mayor pops round to say hello, as does the Catholic Bishop of Down and Connor, Patrick Walsh.

The money raised will go to a variety of causes. A spate of robberies targeting old people has led to this year's special focus on charities for the elderly.

After his sit-out and taking part in half a dozen Christmas services, McKelvey will be "exhilarated but exhausted" tomorrow afternoon. His son is off skiing in the new year but the dean has other plans.

"My wife and I are going to Tenerife. The change of weather will be welcome. I'm not a beach person but I'll take a good novel and sit under my parasol like grandpa grump."

The Black Santa can do sun too!