Yes. The in-season is roughly 50 weeks long. Las Vegas has become so popular in the past 15 years or so that the high season continues throughout the year.
Especially busy times include weekends, holidays, major conventions, and special events (such as the Super Bowl, NCAA Final Four, and any championship boxing match), no matter the month.
Weekends year-round are insane. If you can come Sunday through Thursday, you can often avoid the crush, though not always; most conventions, major and minor, take place during the week.
Traditionally, there are two periods when visitor counts drop and prices fall: July and December. The intense summer heat in southern Nevada, in the past, has kept away the crowds, though family activities and low room rates at the height of the summer attract the Mom, Pop, Buddy, and Sis units. Even today, though, December remains slow, while people are preparaing for the holidays.
Otherwise, it's in-season galore in Las Vegas. With 38.5 million visitors in 2005, visitor counts average out to more than 105,000 every day. Unless you're here the week before Christmas, which is the absolutely slowest few days of the year, be prepared for lots of people trying to do the same things you are.
