Leiden Weather OverviewScoresFors & AgainstsWeatherPhotos Average Temperature Jan 45 °F7 °C Feb 48 °F9 °C Mar 50 °F10 °C Apr 58 °F15 °C May 57 °F14 °C Jun 68 °F20 °C Jul 68 °F20 °C Aug 70 °F21 °C Sep 64 °F18 °C Oct 57 °F14 °C Nov 48 °F9 °C Dec 46 °F8 °C Humidity Jan 72% Feb 73% Mar 70% Apr 61% May 65% Jun 68% Jul 69% Aug 69% Sep 71% Oct 76% Nov 77% Dec 77% Rain Jan 25mm Feb 26mm Mar 48mm Apr 18mm May 18mm Jun 212mm Jul 29mm Aug 27mm Sep 59mm Oct 62mm Nov 44mm Dec 42mm Clouds Jan 90% Feb 56% Mar 71% Apr 42% May 58% Jun 60% Jul 48% Aug 57% Sep 66% Oct 86% Nov 90% Dec 80% Air quality US AQI Jan 21 Feb 21 Mar 28 Apr 34 May 36 Jun 32 Jul 35 Aug 29 Sep 29 Oct 24 Nov 9 Dec 23 Sun Jan 1UVI Feb 1UVI Mar 2UVI Apr 4UVI May 4UVI Jun 5UVI Jul 5UVI Aug 5UVI Sep 3UVI Oct 2UVI Nov 1UVI Dec 0UVI
