Pittsburgh Ranked Cloudiest Major City in the U.S.
Pittsburgh has been ranked as the cloudiest major city in the United States, averaging only 2,021 hours of sunshine annually, according to a report by World Atlas based on NOAA data. December is the cloudiest month, with the city experiencing just eight days of sunshine on average. The city's proximity to the Great Lakes contributes to its persistent cloud cover through a phenomenon known as the lake effect. Cold air moving over the warmer waters of the Great Lakes generates warmth and moisture in the lower atmosphere, leading to cloud formation. Additionally, low-pressure systems often settle near the Great Lakes and Hudson Bay, prolonging storm activity in Pittsburgh. The city's geographical distance from dry air sources like the Rockies and Southwest deserts further limits clear days. 
