If you're trying to plan a vacation one month or more in advance, National Weather Service has an easy to understand climate prediction here.  Weather service forecast links below show current conditions.  Special circumstance like wildfire or road closings as provided by the US Forest Service and National Park Service.  

Coronado National Forest Conditions and Closures National Weather Service, Tucson
Tonto National Forest Conditions and Closures NWS Phoenix
Coconino National Forest Conditions and Closures NWS Flagstaff
Canyonlands National Park NWS Grand Junction
Zion National Park NWS Salt Lake
Dixie National Forest NWS Salt Lake