Rare sunny days wash over Pittsburgh — one of the cloudiest cities in the U.S.

Even with a rare weekend with winter sunshine in the Pittsburgh region, with more ahead this week, it still can sometimes feel like the region’s gray days are endless. And that is close to the truth.

Pittsburgh has an average of just 59 clear days a year, with 306 cloudy days, according to 2018 data from the National Centers for Environmental Information. That makes it one of the cloudiest cities in the country.

You can blame our neighbors to the north, according to Rich Redmond, a meteorologist with the National Weather Service in Moon.

“We have a giant source of moisture just to our north with Lake Erie,” he said.

Cold air sweeps down from the north, picking up moisture as it travels over the Great Lakes, often parking over Pittsburgh and Western Pennsylvania for long periods of time. That’s what was happening at the beginning of the year, Redmond said.

“If you keep airflow like that for a long period of time, you’re just going to have clouds day after day after day,” he said.

Of the 200 largest U.S. cities, Pittsburgh ranks third for cloudy days — depending on how you’re counting.

Its 306 cloudy days a year, on average, put it behind Buffalo (311) and Seattle (307). Anchorage, Alaska, and Rochester, N.Y., round out the top 5, with an average of 304 cloudy days each.

However, this includes partly cloudy days, in which clouds cover 40% to 70% of the sky. Things look a little brighter for Pittsburgh if you count only days of heavy clouds, when 70% or more of the sky is covered.

By that measure, Pittsburgh falls to ninth place, with 203 days of heavy cloud cover every year.

Anchorage holds the top spot with 239, and Seattle is the runner up with 226.

December, January and February are tied for the Pittsburgh region’s cloudiest months, with an average of three clear days and six partly cloudy days each.

The cloudiest spot in America, according to the National Centers For Environment Information, is Cold Bay, Alaska. The tiny town of about 140 people has an average of only 10 clear days a year.

Longing for some sun? The Southwest has you covered. Phoenix leads the country as the sunniest major city, with 211 clear days a year. Las Vegas is a close second at 210.

Or you could stick around. Cold air from the Northeast — which bypassed the Great Lakes — that swept in over the weekend and pushed the clouds away could keep the sunshine around most of the week, according to Redmond.

“We don’t have any real weather makers coming until maybe the end of the week,” he said.

Then those familiar gray skies likely will return next weekend.