1
Start with a bag that are able to absorb the rain. Waterproof backpacks or excellent rain coverings will keep anything inside.
2
A lightweight rain jacket or poncho and a small umbrella can keep you dry when the clouds are open.
3
You should pack clothes made of synthetic or quick-dry fabric and bring a backup pair of dry socks/shoes.
4
You should keep your devices, paperwork and wet stuff separate using ziplock bags or dry pouches inside your backpack
5
You should bring tissues, bug repellant, and a small first aid kit.
6
You should bring a fully charged power bank, download offline maps, and protect your devices with waterproof coverings.