As winter weather envelops the homes of New England, our thoughts naturally turn to warmer days and maybe a beach house on Cape Cod. Of course, if you intend to rent such a house for a week next summer, it’s pretty much a roll of the dice. You could get lovely weather or it could rain every day. However, if you plan to buy a beach house on Cape Cod, you really only need to understand the climate. The sunny summer days will far outnumber the wet ones.