Local climatological data.
Philadelphia, Pennsylvania :
annual summary with comparative data.

APA Citation

National Climatic Center., National Climatic Data Center (U.S.). Local climatological data: annual summary with comparative data. [Asheville, N.C.: National Oceanic and Atmospheric Administration, Environmental Data and Information Service, National Climatic Center.

MLA Citation

National Climatic Center, and National Climatic Data Center (U.S.). Local Climatological Data: Annual Summary With Comparative Data. [Asheville, N.C.: National Oceanic and Atmospheric Administration, Environmental Data and Information Service, National Climatic Center,