The ideal time to explore the Mahishamardini Cave in Mahabalipuram is during the winter season, which extends from November to February. During these months, the weather in Tamil Nadu is pleasant, with moderate temperatures ranging from 20°C to 25°C (68°F to 77°F), which makes sightseeing comfortable. The humidity is also comparatively lower, and there's minimal rainfall, ensuring that your visit is not disrupted by unexpected showers or extreme heat which is prevalent during other times of the year. This period also coincides with a number of local festivals which can add an additional cultural dimension to your visit.
If you're aiming to avoid the crowds and get some serenity during your visit to the cave, consider planning your trip on a weekday early in the morning or late in the afternoon. Tourist influx is usually higher on weekends and during holidays. Since the cave is an architectural marvel with intricate carvings, the soft sunlight of the early morning or late afternoon can augment the visibility of the details in the rock-cut sculptures, making it a perfect time for photography enthusiasts as well. Regardless of when you visit, ensure to bring a hat, wear comfortable shoes for walking, and carry enough water to stay hydrated.