Do I need a heavy raincoat?

No. It is hot and humid even when it rains. A heavy coat will make you sweat more than the rain makes you wet. Use a lightweight, breathable shell instead.

Will my stuff get moldy?

Yes, if you leave it in a dark, damp bag. Keep your zippers open when in your room to allow airflow and place silica packets in your luggage to absorb excess moisture.

Packing for Monsoon Season in Southeast Asia

Prioritize quick-drying fabrics and waterproof gear to handle sudden, heavy downpours. You need to keep your electronics sealed in dry bags and accept that you will eventually get wet regardless of your gear.

Choose synthetic fabrics. Avoid cotton entirely; it stays heavy and cold when wet and takes days to dry in high humidity. Pack polyester, nylon, or merino wool blends that wick moisture and air-dry in under 4 hours.
Protect your electronics. Buy a 10L or 20L dry bag for your daypack. Put your laptop, camera, and passport in the dry bag inside your backpack every time you move between locations.
Select footwear carefully. Wear hiking sandals with good grip or lightweight, breathable trail runners. Leather shoes will be ruined by mold and water; leave them at home.
Manage your damp gear. Bring three large gallon-sized Ziploc bags. Use them to isolate damp swimsuits or rain-soaked shirts from the rest of your clean, dry clothing inside your luggage.

Do I need a heavy raincoat?: No. It is hot and humid even when it rains. A heavy coat will make you sweat more than the rain makes you wet. Use a lightweight, breathable shell instead.
Will my stuff get moldy?: Yes, if you leave it in a dark, damp bag. Keep your zippers open when in your room to allow airflow and place silica packets in your luggage to absorb excess moisture.