Boulder, CO Weather OverviewScoresFors & AgainstsWeatherPhotos Average Temperature Jan 45 °F7 °C Feb 37 °F3 °C Mar 46 °F8 °C Apr 61 °F16 °C May 59 °F15 °C Jun 73 °F23 °C Jul 84 °F29 °C Aug 82 °F28 °C Sep 79 °F26 °C Oct 59 °F15 °C Nov 51 °F11 °C Dec 45 °F7 °C Humidity Jan 47% Feb 54% Mar 55% Apr 50% May 60% Jun 46% Jul 45% Aug 41% Sep 36% Oct 37% Nov 57% Dec 46% Rain Jan 25mm Feb 14mm Mar 36mm Apr 21mm May 39mm Jun 80mm Jul 40mm Aug 20mm Sep 22mm Oct 14mm Nov 11mm Dec 4mm Clouds Jan 35% Feb 34% Mar 39% Apr 43% May 46% Jun 34% Jul 20% Aug 21% Sep 21% Oct 19% Nov 34% Dec 38% Air quality US AQI Jan 26 Feb 18 Mar 16 Apr 17 May 20 Jun 23 Jul 23 Aug 28 Sep 24 Oct 22 Nov 26 Dec 29 Sun Jan 2UVI Feb 3UVI Mar 5UVI Apr 7UVI May 7UVI Jun 8UVI Jul 11UVI Aug 9UVI Sep 8UVI Oct 5UVI Nov 3UVI Dec 2UVI
