If you go early enough before the monsoons are really bad, you might be able to take a house boat cruise in the backwaters in the south. I wish I would have done that, but the monsoons made it too dangerous when I was there
:( Even with the monsoons, it was still ‘refreshing’ to see the heavy rains and lightning/thunder storms, as well as getting the Ayurvedic massage (the best time to get this massage is during monsoon)