The lunar month’s highest tide occurred on 18th April for Waitemata harbour and 19th April for Great Barrier Island.
The Waitemata harbour tidal gauge measured a mean level of 1.58 metres between 9:30pm and 9:45pm on 18th April which is 7cm below the April average (2015-2021). The barometric air pressure at the time of the reading was 1021.7 hPa, so when using the inverted barometric adjustment calculation method of 1cm for every 1 hPa, the projected height would have been 1.67 metres at the mean sea level pressure of 1013 hPa. More on meteorological effects on tides can be found here.
The ongoing trend between 2014 to 2022 for the Waitemata harbour sea level peak is downward. The tidal gauge data used for this analysis can be found here.
The Great Barrier Island tidal gauge measured a mean level of 1.09 metres between 08:30am and 08:45am on 19th April. The air pressure at the time of the reading was 1021.5 hPa, so when using the inverted barometric adjustment calculation method of 1cm for every 1 hPa, the projected height would have been 1.17 metres at the mean sea level pressure of 1013 hPa. More on meteorological effects on tides can be found here.
The ongoing trend between 2014 to 2021 for Great Barrier Island sea level peak is slightly upward. The tidal gauge data used for this analysis can be found here.
