Epoxy coated steel or stainless steel or copper Galvanized steel would be best. Even the carbon steel mesh used on 1860's houses has lasted more than a hundred years in dry heat.
Fiberglas would handle rain better but it has plasticiser chemicals that evaporate in the hot sun and due to ultraviolet radiation. It would turn turn white and brittle.
Aluminum would not be affected much by the heat but the rain would start the corrosion process. Then it starts getting quickly brittle and falls apart. Black coated aluminum would be better.
Quality of material makes a difference too. I have used Galvanized wire made in the USA and China and the chinese wire diameter is smaller and the galvanizing is poor, the material rusts which should not happen.