I think this will help u. https://www.hellotravel.com/deals/81196.html Kerala has three tourist seasons. Peak Season which ranges from September to March, Off Season in Kerala which is from April to May and Monsoon Season from June to August . Each season in Kerala is unique making it an ideal destination for tourists who are coming for different kinds of travel experiences in each of these seasons and Best Time to Visit Kerala varies based on why you are visiting Kerala.
Plan post monsoon so that rain will not bother you while site seeing.
places to visit,
Munnar
Allepy
Vembanad lake
Varkala beach
kochi
Athirapalley waterfalls