As for Sharm El Sheikh, Hurghada, Marsa Alam, Taba, Dahab, El Gouna, El Qousseir, El-Tor, Tiran Island, Nabq Nature Reserve, Nuweiba, Port Ghalib, Port Safaga and Ras Sudr, swimming is pleasant in december. The sea water is 77°F on average (min: 73°F/max: 80°F) so you can easily spend time in the water.