Dive into the Challenge: HALF IRON OCEANSIDE in California Swim: Oceanside Harbor's pristine waters await you for a challenging counterclockwise loop swim. With an average water temperature of 61°F / 16°C, it's the perfect start to kickstart your race and invigorate your senses. Bike: Embark on an exhilarating cycling adventure, starting from Oceanside Harbor and venturing through the iconic Camp Pendleton. Conquer San Mateo Hill and other formidable climbs before facing the flat roads and ...