Jamestown Weather OverviewScoresFors & AgainstsWeatherPhotos Average Temperature Jan 75 °F24 °C Feb 77 °F25 °C Mar 79 °F26 °C Apr 77 °F25 °C May 75 °F24 °C Jun 73 °F23 °C Jul 72 °F22 °C Aug 70 °F21 °C Sep 68 °F20 °C Oct 70 °F21 °C Nov 72 °F22 °C Dec 73 °F23 °C Humidity Jan 70% Feb 69% Mar 69% Apr 66% May 67% Jun 61% Jul 61% Aug 64% Sep 66% Oct 69% Nov 68% Dec 67% Rain Jan 5mm Feb 3mm Mar 4mm Apr 7mm May 5mm Jun 100mm Jul 6mm Aug 7mm Sep 5mm Oct 5mm Nov 4mm Dec 7mm Clouds Jan 73% Feb 42% Mar 64% Apr 56% May 49% Jun 57% Jul 65% Aug 79% Sep 83% Oct 75% Nov 59% Dec 59% Sun Jan 7UVI Feb 10UVI Mar 8UVI Apr 8UVI May 7UVI Jun 6UVI Jul 5UVI Aug 6UVI Sep 6UVI Oct 6UVI Nov 8UVI Dec 8UVI