Las Vegas has a subtropical, hot desert type of climate with hot and dry summers and mild winters. Rainfall is scarce throughout the year.
Summer: From May to September, the weather is extremely hot. This is especially because of its location in a desert. The temperatures are usually around 30 degree Celsius. Although not a popular season for tourists, this is a great time to plan a family trip to Vegas.
Fall: October to November is probably the best time to visit Las Vegas, the weather is pleasant and the December crowds aren't here yet! There is some respite from the scorching heat.
Winter: December to February is the coldest period of the year. Days are chilly but the nights are very cold. Temperatures average around 8 – 10 degree Celsius.
Spring: March and April see a rise in temperatures as compared to the winter months. Though not peak season, yet lots of people flock over to Las Vegas during these months for some great fun.
The best times to visit Las Vegas are from March to April (Spring) and from October to November (Fall), as the temperatures are extremely pleasant for a prolonger visit. Autumn is usually considered peak season, and one might find lots of crowd and high prices in hotels during this period.