Casa Grande, AZ Weather OverviewScoresFors & AgainstsWeatherPhotos Average Temperature Jan 61 °F 16 °C Feb 60 °F 16 °C Mar 72 °F 22 °C Apr 81 °F 27 °C May 81 °F 27 °C Jun 97 °F 36 °C Jul 102 °F 39 °C Aug 100 °F 38 °C Sep 93 °F 34 °C Oct 84 °F 29 °C Nov 75 °F 24 °C Dec 61 °F 16 °C Humidity Jan 57% Feb 54% Mar 38% Apr 20% May 25% Jun 15% Jul 24% Aug 39% Sep 45% Oct 21% Nov 35% Dec 66% Rain Jan 12mm Feb 28mm Mar 6mm Apr 4mm May 3mm Jun 3mm Jul 9mm Aug 20mm Sep 19mm Oct 3mm Nov 26mm Dec 27mm Clouds Jan 24% Feb 31% Mar 14% Apr 9% May 9% Jun 2% Jul 13% Aug 12% Sep 8% Oct 1% Nov 22% Dec 22% Sun Jan 4UVI Feb 5UVI Mar 8UVI Apr 9UVI May 9UVI Jun 10UVI Jul 11UVI Aug 10UVI Sep 9UVI Oct 6UVI Nov 4UVI Dec 3UVI