Q.Will Hydrangeas grow in Las Vegas, NV
The temperature in Vegas can exceed 100 degrees in summer, except along one wall in my yard. The rest of the yard has full sun. How well will Hydrangeas do here?

Hydrangeas are famous for not liking extremely hot weather, but that's no reason not to try 1 or 2 to see how they do. This article will give you some tips about dealing with the hot temps: https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/drooping-hydrangea-plants.htm