Hi, Feb would be a good month for Kerala. Munnar is a hill station so would be colder. Beach side would also be pleasant in month of Feb. You can plan for -
1. Munnar - Do not miss Eravikulam National Park.
2. Alleppey - One night at Houseboat. Beaches are also beautiful.
3. Kochi - Roam around fort kochi, have a seaside dinner at any good restaurant here.
4. Thekkady - Periyar National Park is most important here!
Happy Traveling!