Fairfax, VA Weather OverviewScoresFors & AgainstsWeatherPhotos Average Temperature Jan 37 °F 3 °C Feb 44 °F 7 °C Mar 46 °F 8 °C Apr 66 °F 19 °C May 77 °F 25 °C Jun 81 °F 27 °C Jul 86 °F 30 °C Aug 84 °F 29 °C Sep 81 °F 27 °C Oct 66 °F 19 °C Nov 50 °F 10 °C Dec 45 °F 7 °C Humidity Jan 72% Feb 67% Mar 55% Apr 62% May 77% Jun 72% Jul 74% Aug 77% Sep 70% Oct 69% Nov 63% Dec 71% Rain Jan 62mm Feb 48mm Mar 51mm Apr 50mm May 96mm Jun 72mm Jul 64mm Aug 86mm Sep 42mm Oct 60mm Nov 74mm Dec 45mm Clouds Jan 52% Feb 55% Mar 38% Apr 51% May 41% Jun 39% Jul 18% Aug 30% Sep 20% Oct 40% Nov 32% Dec 45% Air quality US AQI Jan 125 Feb 131 Mar 123 Apr 108 May 113 Jun 111 Jul 104 Aug 73 Sep 97 Oct 104 Nov 110 Dec 118 Sun Jan 2UVI Feb 4UVI Mar 4UVI Apr 6UVI May 8UVI Jun 8UVI Jul 9UVI Aug 8UVI Sep 7UVI Oct 5UVI Nov 2UVI Dec 2UVI
