Roof shingles containing tar are a bad idea for hot regions. The heat from the sun will melt the tar out of the shingles and can be disastrous for the roofing. In fact if you carefully look at the building rules and codes you will note that all type of organic and tar roof shingles are barred for regions which have hot weather. These type of shingles also can't handle the wide variations of temperatures normally seen in deserts between day and night time temperature.
Choosing the right...