The council is urging people to stay out of the sea today and resist the temptation to go for a Christmas Day dip.
The sea temperature is forecast to be a chilly 48F or 9C. With the tide going out until 12.50pm, it could prove hard to get up the steep shingle and out of the water.
The air temperature is expected to reach a maximum of 50F or 10C, with a light south westerly breeze and low cloud but no rain.
Despite the conditions, Brighton and Hove City Council seafront officer Abby Rocky warned festive dippers to be wary of the risks.
She said: “We understand people will be considering a Christmas Day dip this year but winter sea conditions, cold water and strong currents can be extremely hazardous for even the most experienced sea swimmers.
“Cold water sea swimming takes skill, stamina and knowledge of the physical dangers and should only be for the very experienced, using suitable wetsuits, in very calm conditions and with friends.
“Even on a calm day, sea currents, unpredictable waves or a sudden change in weather can create life-threatening hazards without warning.”
Swimmers are advised to check the weather forecast and sea conditions on the day, consider others in their group and never enter the water after drinking alcohol or taking drugs.
Ms Rocky said: “The sea will be there tomorrow. Don’t take unnecessary risks that could threaten your life or others trying to help.”
She added that, unlike many other beaches where you can gradually enter the water, Brighton and Hove beaches have a steep shingle slope, making it hard to get in and out of the water, especially at high tide.
When the wind picks up, it can combine with the steep shingle banks to create powerful waves close to the shore and increase the risk of being swept out to sea.
She added: “There is no lifeguard service at this time of year. If you get into difficulty, you are putting extra pressures on emergency services and volunteers like HM Coastguard and the lifeboat service.
“If you get into trouble in the water, try to stay calm and float on your back, spreading your arms and legs moving your hands and try to get someone’s attention.
“And if you see anyone in danger or attempting to enter the water in dangerous sea conditions, dial 999 and ask for the coastguard.”
A new leaflet giving advice and information about sea swimming has been produced by the council’s seafront team and is available from the Seafront Office
The Brighton Seafront Office is open daily from 9am to 5pm and can be contacted on 01273 292716.
Councillor Mitchie Alexander, the council’s cabinet member for culture, heritage and tourism, also urged people to stay safe and look out for their friends and family on the seafront.
She said: “Everyone enjoys a bracing stroll on the promenade over the festive season. But we would urge people to keep away from the groynes, staying on the path or high up on the beach, especially when the sea conditions are rough.
“Keep little ones close and hold their hands when walking on the beaches. Keep dogs on leads and don’t let them enter the sea.”