There have been an arguement about this but. I would love to confirm with anyone who is completely sure of this. Will U.S citizens need a VISA for traveling to brazil during the months of June through september?
No, according to the Consulate General of Brazil website. It is only good from June 1 - September 18.
http://atlanta.itamaraty.gov.br/en-us/tourist_visa.xml - consulate general of Brazil
http://www.reuters.com/article/us-brazil-olympics-visas-idUSKBN0UD1C720151230