Walnut Canyon National Monument, at 6,900’ elevation, gets approximately 20” of precipitation per year. About 2/3 of this amount comes as rain during late summer monsoons; winter snowfall (58” on average) supplies the rest. Temperatures typically range from near 0 in winter to the mid-90s in summer.
But be prepared. Weather in northern Arizona varies tremendously with elevation. Above 10,000’ on the San Francisco Peaks, annual precipitation exceeds 40 inches, temperatures are considerably cooler, and the growing season is remarkably shorter. And 30 miles to the northeast lies desert - at 4500’, the Little Colorado River Basin typically receives less than 7” of rain each year.