There are a lot of advantages to traveling during the off season including lower plane fares, cheaper hotels, better room choice, and shorter lines at the airport and your destination. While for many locations summer is the busiest time of year, every location is different and has its own busy time such as winter for ski destinations. Crowdlevel.com offers information to help you avoid the crowds.
Charts of monthly historical arriving passenger totals for several popular US airports / destinations:
Crowdlevel.com provides information about crowd levels: knowing how crowded a particular location or venue has been in the past can help predict how crowded it will be in the future. This when to go information can assist in planning a trip to avoid the crowds. An example of a question the site helps answer: "When is the least crowded time to go to Disney World in Florida?". The site lists the number of passengers arriving monthly at US and international airports.
