When I lived in Vegas some 20-odd years ago, we figured that the first 100-degree day would be right around the end of May--Memorial Day weekend. And so it proved; April, by contrast, was almost always warm and pleasant, with highs in the 80s. However, in recent years, it's hit 100 before the end of April. The forecast for the next few days is for a high of 98--so it may hit triple digits again.
This, of course, is due to that imaginary liberal climate change hoax that all the SOCIALIST Democrats keep bleating about. Biden and all the environmentalist wackos want to destroy the country. We have only Tucker Carlson to stem the tide of liberal nonsense. It's not really gonna be 100 degrees this weekend. Temperature forecasts are the tool of the Deep State. I'm sure Hillary's behind it all.
Nonetheless, if you have travel plans for this summer, you might want to reconsider whether you want to be in Vegas two or three months after it's already hit 100. There are many other ways to lose your money, and without suffering heatstroke in the process. IMHO scheduling a vacation for Vegas in July (on purpose!) is like scheduling a vacation for Fairbanks in January. (But Fairbanks doesn't have slot machines!!!)
(And don't think you'll be able to use the pool, peasant, without ponying up--even if you are staying at the hotel, and even if you are already paying a resort fee. "Resort" doesn't mean "pool." You heard it here first.)