We have visited Oahu (Waikiki) Jan 3 to Feb 22 for 25 years. I can only recall one time with a 3 day wash out. Other than that a one day rain event and usually sporadic rainfall. Even then it beats snow and ice. At night it occasionally gets down to between 68 and 70 and the locals put on sweaters, coats, ski-masks, etc. Tee shirts are still fine for us mainlanders.