Notices. 1  2017-08-27: Support will be closed on Monday, September 4, 2017 for the Labor Day statutory holiday; we will reopen at 7am (Pacific) September 5. 2  2017-08-02: Introduction to Intranet Administration Webinar | September 6, 2017 | REGISTER NOW.
The weather varies greatly throughout the year in Las Vegas â the winter months are dry and cold with short days and long nights, whilst the summer months are blisteringly hot with long days and short nights. Las Vegas is located in Nevada in the Mojave Desert.
Hottest Temperature in September in Las Vegas History. The warmest it has ever gotten in the Vegas valley during September is 113 degrees. This happened on September 1, 1950. As you might expect, the absolute hottest time in Las Vegas is around Labor Day, when September is basically an extension of summer.