Seconded, for the love of God.
In the last week or two (since that hurricane / tropical storm came up into the Gulf of Mexico), Las Vegas has been getting thunderstorm clouds rolling thru. Some of them cruise right past (or over) the valley without affecting us much, and some of them have dumped a whole mess of rain and wind (and a little hail) on us. The temps tend to be a little lower when this happens, but it’s not like that’s going to make you want to go outside in that crap. Prior to 2 weeks ago, we were experiencing a couple of weeks of record heat (113-117 degrees) – I think we had at least 5 straight days of temps of 115 or above. If you’re going to be away from Green Valley Ranch between 10am and 5pm during your stay, you’d also be well-advised to carry a bottled water or two with you.