Kauai, Hawaii Weather OverviewScoresFors & AgainstsWeatherPhotos Average Temperature Jan 68 °F20 °C Feb 64 °F18 °C Mar 66 °F19 °C Apr 70 °F21 °C May 72 °F22 °C Jun 73 °F23 °C Jul 75 °F24 °C Aug 75 °F24 °C Sep 75 °F24 °C Oct 75 °F24 °C Nov 72 °F22 °C Dec 70 °F21 °C Humidity Jan 75% Feb 77% Mar 76% Apr 77% May 82% Jun 80% Jul 83% Aug 83% Sep 84% Oct 82% Nov 84% Dec 84% Rain Jan 48mm Feb 151mm Mar 92mm Apr 103mm May 88mm Jun 190mm Jul 100mm Aug 166mm Sep 186mm Oct 140mm Nov 180mm Dec 231mm Clouds Jan 27% Feb 45% Mar 45% Apr 40% May 46% Jun 45% Jul 38% Aug 45% Sep 51% Oct 43% Nov 49% Dec 56% Sun Jan 7UVI Feb 8UVI Mar 8UVI Apr 9UVI May 9UVI Jun 9UVI Jul 10UVI Aug 9UVI Sep 9UVI Oct 8UVI Nov 6UVI Dec 5UVI