IRONMAN 70.3 Oceanside is a triathlon event located in Oceanside, California, that consists of a 1.2-mile swim, 56-mile bike ride, and 13.1-mile run. The race takes place in April each year, typically with mild to warm temperatures and low to moderate humidity. The swim portion of the race takes place in Oceanside Harbor, where athletes start in a rolling start format and swim clockwise around the harbor. The water temperature is usually around 60-65 degrees Fahrenheit, so wetsuits are ...