Are the tide predictions actual measurements?

No.

The tide times and heights shown on UK Tide Times are predictions rather than live measurements of the sea.

A tidal prediction provides an expected time and height for high tide and low tide based on tidal data and established prediction methods. The actual sea level can differ from the predicted value.

Weather conditions such as strong winds, storms and changes in atmospheric pressure can affect the actual height and timing of the tide. Local coastal conditions can also influence the sea level.

For this reason, tide predictions should be used as a guide when planning coastal activities and should not be treated as a live measurement or a substitute for official marine forecasts, local warnings or other safety information.