Arizona does not observe daylight savings. You are on Mountain Standard Time. Leave Flagstaff with a full tank of gas and food as there are no services at the monuments. Expect windy conditions most of the year. Spring is usually mild but heavy snowfall can occur.
Summer days are warm with temperatures in the eighties.
Afternoon thunderstorms likely July to September. Winter days can be cold, snow and ice can cause temporary closure of the Island Trail. By personal vehicle or tour bus. Nearest commercial airport is located in Flagstaff, Arizona. Trail accessibility is limited because of terrain.