Visiting the Baths of Caracalla during peak season, which runs from June to August, can be a crowded experience. The Baths attract a lot of tourists during this period, so you may have to deal with long queues and wait times. On the bright side, the weather during this time is usually pleasant and ideal for outdoor exploration.
The low season is in spring between March and May and also in autumn from September to November. Visiting during this time offers a quieter and more relaxed atmosphere at the Baths. The number of visitors is significantly lower, which means you can take your time to appreciate the ruins and enjoy the tranquil surroundings. However, keep in mind that the weather during this period can be chilly, so ensure you dress warmly.