Waves up to 15ft high are expected to batter the coast at Redcar on Sunday, lifeboat rescuers are warning.
The rough weather is expected to peak at about 1700 GMT and fishermen and walkers are being urged to avoid the area.
The RNLI said the waves would break over the sea wall and urged visitors not to be tempted to come and watch the rough seas.
A spokesman said it would be difficult to rescue anyone swept out to sea.
Dave Cocks, spokesman for the Redcar RNLI, said: "The forecast for this weekend means there are likely to be very rough seas, particularly on Sunday.
"The latest prediction is for waves up to 15ft high, which will definitely mean the sea will be breaking over the sea wall.
"A couple of years ago we had to assist an elderly gentleman who was struck to the ground by a large wave breaking over the wall, causing him to break all three major bones in his arm."