I am planning a vacation in Arizona,Nevada and Utah the middle of next May.I am interested in what the weather is like. Thank you Marilyn

The weather in May should be very good for those three states depending on where you are talking about. Phoenix, Las Vegas, Tucson and similar elevations should be pretty warm but not exceptionally hot. UTAH should be pretty good at lower elevations. Lake Tahoe could be pretty chilly. It all depends on what you like. May would probably be my choice to travel in these states. BTW, I have lived and traveled extensively in this area at all times of the year. We are warm weather folks so my recommendation is from that perspective.

Thank you for answering my weather question.

For climotological data for over 300 US cities, check out

nimbo.wrh.noaa.gov/Hanford/climo/national.htm

Phoenix usually hits the 100 degree mark for the first time in mid-May. With the low humidity, 100 degrees really isn't too bad.
Keep in mind that elevation plays a big role in temperature. As you travel throughout the southwest, expect 20 to 30 degree temperature differences between the high country and deserts.