San Diego weather is often the weather that laughs at you. For some reason, the forecast will say clear skies and clouds will roll in off the ocean, or the forecast will tell you to wear a jacket for an overcast day and the sun will come out to play.
Key Difference: Oceans are large bodies of water that exist on the Earth. Oceans and seas are both bodies of water and these terms are often used interchangeably due to their lack of proper definition. Water bodies make up the hydrosphere that covers 71% of the Earth. Oceans and seas have slight differences among them.
The difference between a sea and a lake largely comes down to permanence. A sea is a more permanent feature, while a lake is relatively temporary. This time frame is relative, and should be examined on a scale of millions of years. On a geological scale that includes and measures other massive, slow events such as ice ages and plate shifts, a lake is a temporary feature.