Rain City Water Polo was formed in December 2010 by a small group of water polo supporters (Evan Kaseguma, Sarah Hoisington, Melissa Lloyd & Kelly Sterling) that were committed to providing youth athletes with an opportunity to play water polo year-round in a fun and positive environment. During its first month of existence, Rain City Water Polo welcomed over 70 athletes into its program. Since then, Rain City has grown into the largest water polo club in Washington.

In February 2013, Bigfoot Water Polo merged with Rain City Water Polo. Under the guidance of Thor Tyson (Bigfoot’s founder), Rain City expanded its presence in the North Seattle area.

In June 2014, Rain City became the only water polo club in the United States to send multiple athletes to the 13-member USA Youth Travel Team (Marco Stanchi and Conrad Gordon). Stanchi and Gordon led the US to a Gold Medal in the UANA Pan-American games and competed in Istanbul, Turkey in the FINA Youth World Championships. In addition, Jake Gordon was selected to the USA Development Team.

In March 2015, three Rain City athletes were selected to the US National Team: Stanchi (Youth), AJ Rossman (Cadet) and Jake Gordon (Cadet). Rossman was selected to the 13-member Cadet Travel Team that competed in Serbia at the Darko Cucic Memorial Tournament. Stanchi participated in the inaugural US National League against Olympians, collegiate All-Americans, and members of the US National Teams.

In March 2016, one Rain City athlete was selected to the US National Team: AJ Rossman (Cadet).