Austin texas/New Orleans in summer

[FastNLoud]

I'm planning a roadtrip from Vegas to New Orleans via Austin Texas but it looks like it will have to be at end of July. Im interested in people's experience of the heat at that time of year. I have been to Vegas a couple of times before and experienced 40+ degrees and that was ok as it's a dry heat (and you are never far from an air conditioned casino). However Austin/New Orleans sounds hot and humid, has anyone been during the summer and how did you find the heat?