Being a seaside city, you can visit Atlantic City anytime of the year you want. There are two peak tourist seasons. One falls between March-May, before the Labor Day celebrations when fares and rates are still affordable, making it ideal if you’re traveling on a budget.
If you want complete AC (Atlantic City) experience with warm sunny days where you spend your time on the beach and try your hand at gambling by night, visit the city from June - August known as the busiest months of Atlantic City. During these months, the rates are sky high and there are crowds everywhere. If you’re on a budget constraint and have a dislike of crowds, avoid AC during these three months.
September-February is AC’s off season, as winter begins to set in. Rates drop as the influx of visitors reduces. Apart from the New Year’s period, winter is quite a low-key scene at Atlantic City. Most of the attractions too shut down once the cold sets in.