In 1998, Ágúst took over as head coach of the joint Grótta/KR women's team for the rest of the 1997-1998 season after Andrés Gunnlaugsson was fired.
[2] Under his watch the team won the Icelandic Women's Handball Cup but was knocked out in the Final 8 in the national championship playoffs after losing to Fimmleikafélag Hafnarfjarðar.
[3] He resigned from hist post after the season to take over as the head coach of the Iceland women's national handball team.
[14] Shortly later he was hired as an interim coach for HK men's team to finish out the season, replacing Samúel Ívar Árnason.
[22] In March 2000, Ágúst was hired as the head coach of the Iceland women's national handball team.
In August 2018, Ágúst was hired as the head coach of the Faroe Islands women's national handball team.