September in Las Vegas begins hot but temperatures moderate as the month progresses. Nights tend to be more comfortable.
Afternoon high temperatures tend to be near 99 F (37 C) early in September, but will cool to near 90-91 F (32-33 C) near the end of this month.
A few of the warmer afternoons, especially early in the month, can reach up near 105 F (40-41 C).
The record high temperature in Las Vegas during September is 114 F (45.6 C).
Late night and early morning lows tend to be around 73-75 F (23-24 C) early in the month but fall to 65-66 F (18-19 C) near the end of this month.
A few of the cooler mornings, especially late in the month, can dip down near 57 F (14 C).
The record low temperature for Las Vegas during September is 46 F (7.8 C).
Sun and Rain
Las Vegas in September offers lots of sun with little rain risk. Expect, on average, about 22 sunny, 6 partly sunny and only 2 cloudy days.
Rain is sparse, with measurable rainfall occurring only on 2-3 days, on average, with rainfalls of 0.5 inches (13 mm) or more occurring only about once every 5 years.
The number of daylight hours this month decreases from about 12.9 hours on the first to about 11.8 hours by the 30th.
The wind in Las Vegas this month is mostly light to gentle, averaging 4-12 mph (6-19 kph) but briefly can be moderate at 13-18 mph (20-28 kph).
What to Wear in Las Vegas During September?
Summer begins to relent this month with more comfortable nights and moderating afternoon temperatures.
Light summer attire is still recommended such as shorts, sandals, skirts, T-shirts, sundresses, and tank tops but keep in mind there are specific dress codes for casinos, restaurants, bars, and nightclubs.
You should also pack a light sweater for the cooler evenings later in the month. Don’t forget your sunscreen, sunglasses, and a good pair of walking shoes.
Things to Do in Las Vegas During September
Although temperatures will usually be a bit cooler this month, September is still a pretty hot month in Las Vegas, so you might want to consider indoor activities instead of a free walking tour.
September means the return of football, so you can expect the Las Vegas Raiders to play a few home games this month.
There are usually also a few NASCAR events as well. Look for sporting events in Las Vegas.
For more ideas, read our full post on things to do in Las Vegas in September.