Average Temperature in Maryland:

SPRNG: 67 F
SUMMER: 80’s F
FALL: 40-60 F
WINTER: 20-30 F
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You can find more information on weather around the U.S. at the Weather Channel.

Tourism

The following websites provide useful information about tourism opportunities in College Park,Washington, DC, and the surrounding areas.

College Park and Prince Georges County
City of College Park
Prince George County
Maryland Office of Tourism

Washington DC
The Washington DC Convention and Tourism
DC Pages
The Washington DC Registry
The Washington DC District of Columbia
Cultural Tourism DC
Washingtonian

Baltimore
Baltimore Area Convention and Visitors Association
The Baltimore Tourism Association

Annapolis
Annapolis and Anne Arundel County Conference and Visitors Bureau

Maryland Eastern Shore
Maryland's Eastern Shore Guide

Maryland General
Maryland Office of Tourism
HM USA Travel Guide

Virginia General
Virginia Tourism Corporation
The Eastern Shore of Virginia Tourism Commission

Weather
College Park and the surrounding area experience four seasons.  Winter can be very cold, with averages in the 20s and 30s Fahrenheit.  You will need to bring plenty of winter clothing, including a heavy coat, a scarf, and gloves.  On the opposite end, summer can be very hot and humid, with July being on average the hottest month of the year. Be sure to bring plenty of clothing you can wear in very warm weather. Spring is a pleasant time of the year, with the famous cherry blossoms blooming in the area.  Fall can be cool, but is a great time to view the changing colors of the leaves. 
You can find more information on weather around the U.S. at the Weather Channel