Hi Sarah and Sarah. There are swimmers in Brighton all year round, Saturday and Sunday. That said, the water is very cold (currently around 44 degrees) and even the most hardy winter swimmers do not stay in long – maybe 10 minutes tops but if you aren’t acclimated to cold water, even 10 minutes is dangerous. Might be a bit better for you with a wet suit – all I can say is, come out, feel the water, learn the danger signs, and have fun. I should also point out that swimming is technically prohibited off season, so you take a risk.