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