The tide is forecast to rise to 10.2m just after 08:00.
The wind will also combine with the high water to increase the risk of road flooding.
Guernsey Met has issued a yellow tide alert for the period.
A tide alert constitutes a combination of wind, wave, and tide conditions which could cause spillage over sea walls, unprotected quays, and debris thrown onto coastal roads.
Morning wind will be a west to southwest light force three to moderate force four, veering northwest.
Jersey Met has issued an amber tide warning.
— Guernsey Met (@GuernseyMet) February 21, 2023