Although the town is still accessible only by train or light aircraft, its guesthouses are packed during late summer and autumn, when the vast ice-sheet over the bay melts, forcing around 1,000 bears to lollop around for months on the shore.
Lately, however, it is not only polar bear watchers who come flocking.
With the clamour over global warming, it has become a magnet for an army of environmentalists and climatologists who have given Churchill an air of impending doom.
The Arctic ice-cap is shrinking fast, is their message, and as it disappears, so too will the polar bears.
Today, the polar bear population may hover healthily around 25,000 (they live in Russia, Alaska, Greenland, Norway and Canada).
Yet, we are repeatedly warned, if the planet continues to overheat at the present rate, within four decades our biggest carnivore will be extinct, starved to death as its natural hunting grounds disappear.
"Come up and see them while you still can," is the gist of their depressing refrain.
To some Churchill residents, who base their opinions on personal experience rather than fancy charts and computer models, this is so much nonsense put about by scaremongers for their own dubious ends.
When outsiders question whether anyone would be so cynical, they are reminded of that now-famous photograph of a polar bear which appears to be teetering precariously on an Arctic ice-floe, melting faster than ice-cream, in the depths of winter.
For a while, it became a powerful symbol of the perils of global warming - until it was revealed to have been taken three years ago and during the height of summer.
Dennis Compayre raises bushy grey eyebrows as he listens to the environmentalists predict the polar bear's demise.
"They say the numbers are down from 1,200 to around 900, but I think I know as much about polar bears as anyone, and I tell you there are as many bears here now as there were when I was a kid," he says as the tundra buggy rattles back to town across the rutted snowscape.
"Churchill is full of these scientists going on about vanishing bears and thinner bears.
"They come here preaching doom, but I question whether some of them really have the bears' best interests at heart.