There are 13 climatic zones distributed throughout Hawaii and the geography of Oahu boasts many of them because of the diversity of its land. There are the mountains and the beach and so each part of the island offers something different.

There are only two seasons in the state of Hawaii and thus Oahu also has just summer and winter and nothing in between. There is not much temperature difference between the two seasons as well as the day and night variation is also minimum. The humidity of the area is on a general high and there is not much dry season either during the winter or summers.

The place is most often covered with clouds and receives little clear sunshine and a lot of rainfall. There are also the trade winds which provide the island with a natural cooling phenomenon and are perhaps the best thing about the place. There is rain in some part or the other of Oahu every single day. The rain is in most days warm and gentle and does not cause harm to the lives of people who reside in the areas nor the tourists who are looking forward to a good time at the beach.

There are two sides of the island of which the windward side automatically gets more rain as compared to the leeward side which receives much less rainfall per annum. Umbrellas remain an all year round purchase item of Oahu and are a sold everywhere.