Weather in Las Vegas in September

How September compares

September is the 4th warmest month of the year in Las Vegas and ranks 4th of 134 destinations we compare for September - see where else is hot in September. Within United States it is 1st of 6 (United States in September). Against London's average high of 18.6°C in September, Las Vegas is 15.0°C warmer by day and 10.0°C warmer at night.

Daytime and night-time in September

The typical September day in Las Vegas peaks at 33.6°C, but that is an average: the warmest 10% of days reach 37.6°C or more. About 98% of days top 25°C and almost every pass 30°C. Nights average 21.2°C; one night in ten drops to 16.7°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest September day here reached 45.1°C (2020-09-06) and the coldest night 10.3°C (2017-09-24).

Rain in September

Dry (3 rainy days or fewer): about 1 days with 1 mm or more, 7 mm in total. Year to year it varies a lot - the wettest September was 1997 with 53 mm, the driest 1994 with 0 mm. Humidity averages 24%.

Sunshine and daylight

Around 10.3 hours of sunshine a day (estimated from cloud cover), 12.2 hours of daylight: the sun rises about 06:23 and sets about 18:49 local time in mid-September. Average cloud cover is 16%.

Is September a good time to visit Las Vegas?

It is a reasonable choice: hot days - though the heat can be intense at midday. The best months for Las Vegas on our scoring are May, October, April; months averaging 25°C or more: Apr, May, Jun, Jul, Aug, Sep, Oct.

Plan around the heat, not just the sunshine

September is not a reliably gentle month for being outdoors all day: 83% of days reach 30°C, and the hottest 10% reach 38°C or more. Put longer walks earlier in the day and leave room for indoor breaks when the heat feels strongest. Lightweight, loose clothing, a hat and regular drinks are sensible priorities. Evenings should generally feel warm enough for light clothing, although the coolest 10% of nights fall to 17°C or below, so a light layer earns its place in your luggage. This weather suits travellers happy to adjust their pace; it is less appealing if your ideal city break involves walking continuously through the afternoon.

Little rain, but plenty of exposure

With about 10.3 hours of sunshine a day, September gives you plenty of bright weather, but that also means sustained exposure when you are outside. Sunscreen and access to shade deserve more attention in your planning than waterproof clothing. Humidity averages 24%, so the heat is dry rather than muggy; that does not make the afternoon temperatures mild. Rain interrupts relatively few plans, with about 1 rainy day during the month, though a completely rain-free stay is not guaranteed. Keep outdoor arrangements flexible rather than assuming every day will be identical. The main weather compromise is managing heat and sunshine, not working around frequent showers.