A king tide is a higher than normal high tide. King tides peak twice a year, once during the day in summer (typically in January) and once during the evening in winter (typically in July). Spring tides, which are also higher than normal, can be expected approximately one month before and one month after the peak king tide. During this period, high tides typically get higher as the king tide peak approaches.
Effects of king tides
Quite often king tides happen and go unnoticed, having no impact. Sometimes, king tides can cause localised flooding (tidal flooding) to the bayside and low lying parts of nearby suburbs. Areas connected to the foreshore and tide-affected areas of the river, tidal creeks and other waterways can also be affected.
During a king tide it is important to listen out for weather warnings and conditions. Strong on-shore winds can cause wave action and increase water levels. When combined with rain, king tides can cause local drainage systems to have difficulty coping, increasing the chance of localised flooding.
A storm surge can also increase king tide heights to higher than predicted levels. A storm surge is when a low atmospheric pressure meteorological system and strong on-shore winds force sea levels to rise higher than expected.
King tide heights
King tide heights vary. The winter king tide is often a different height to the summer king tide. The summer and winter king tide heights also change year to year.
Find out more about whether your property and area may be at risk of flooding from tidal surges.