Ko Samui Weather OverviewScoresFors & AgainstsWeatherPhotos Average Temperature Jan 79 °F26 °C Feb 79 °F26 °C Mar 81 °F27 °C Apr 84 °F29 °C May 84 °F29 °C Jun 84 °F29 °C Jul 82 °F28 °C Aug 82 °F28 °C Sep 81 °F27 °C Oct 81 °F27 °C Nov 81 °F27 °C Dec 79 °F26 °C Humidity Jan 77% Feb 75% Mar 76% Apr 75% May 77% Jun 77% Jul 75% Aug 75% Sep 78% Oct 76% Nov 75% Dec 77% Rain Jan 101mm Feb 19mm Mar 11mm Apr 31mm May 116mm Jun 167mm Jul 103mm Aug 88mm Sep 97mm Oct 137mm Nov 79mm Dec 34mm Clouds Jan 59% Feb 26% Mar 30% Apr 66% May 82% Jun 91% Jul 77% Aug 91% Sep 88% Oct 70% Nov 68% Dec 54% Sun Jan 8UVI Feb 11UVI Mar 10UVI Apr 9UVI May 7UVI Jun 6UVI Jul 7UVI Aug 6UVI Sep 6UVI Oct 7UVI Nov 7UVI Dec 8UVI