Tidal Range

The vertical difference between a high water and an adjacent low water.

A falling-tide range is measured from high water to the following low water, while a rising-tide range can be measured from low water to the following high water. Range varies through the spring-neap cycle and with longer astronomical constituents and local geography.

Observed range can differ from prediction because wind, atmospheric pressure, river flow and other non-tidal effects alter one or both levels. Tidal range is a height difference and should not be confused with the rate or strength of a tidal stream.