MOSCOW — For anyone who braves the Russian winter, overcast skies and short, dark days are a depressing reality.

But even those bleak expectations were shattered in December, when Moscow was shrouded in an unrelenting cloud cover for all but six minutes.

It was the darkest December in the capital since the city began recording the data, the previous worst having come in 2000, when the sun checked in for a meager three hours.

The average amount of sunlight for December — 18 hours — is hardly anything to write home about.

“When they hear about this, many people say, ‘It’s clear now why I was depressed,’ ” said Roman Vilfand, the director of Russia’s Weather Service, according to the news agency Tass.