We investigate how wind speed at the height of a wind turbine changes during El Niño and La Niña years and with season and time of day in southeastern Australia. We found that El Niño and La Niña can cause average wind speed differences of around 1 m s^-1 in some regions. The highest wind speeds occur in the afternoon or evening around mountains or the coast and during the night for inland areas.  The results help show how placement of wind turbines can help balance electricity generation.