What is the ideal weather near Mersea Island for beach days and sailing excursions?

During the warm season, the weather near Mersea Island is ideal for beach days and sailing excursions, with July being the warmest month with highs around 21°C. November through March marks the cold season on Mersea Island where temperatures dip down to 3°C at night. Many Mersea Island rentals close down for winter, but campers can still find rental cottages available year-round.