It is rainy season in Kerala right now, and it runs October to November. The rain tends to come hard and short rather than all day, and it stays warm through it — so the thing to bring is a shell you can fold into a day bag, not a coat.
Going in December
The dry, bright half of the year, and the reason the backwaters are booked out in January.
What this means for your bag
Real sun protection
High-factor sunscreen, a hat with a brim and sunglasses. Reef-safe sunscreen is worth buying before you go — it is expensive and hard to find at the beach.
See the Beach & Pool Kit packQuick-dry fabrics
Cotton takes two days to dry in this air and starts to smell before it does. Synthetics and merino wash in a sink and are wearable by morning.
See the Summer Sun Kit packInsect protection
Standing water means mosquitoes, and the ones out at dusk are the ones that matter. Repellent with DEET or picaridin, and long sleeves in the evening.
See the Health & Wellness pack
Build a packing plan around the season you are actually travelling in.