Will my clothes mold in my bag?

If you leave damp clothes in a closed bag for more than 24 hours, yes. Always use a mesh laundry bag or a dedicated pocket for worn items to allow airflow until they can be washed.

Is it better to buy clothes there?

Yes. If you find yourself struggling with the heat, buy local, lightweight linen trousers or loose-fitting shirts in the markets. They are designed for the climate and are very inexpensive.

Should I bring a rain jacket?

Only if you are traveling during the rainy season. Otherwise, a thin, packable poncho is sufficient. Heavy waterproof jackets will just trap sweat and make you wetter from the inside out.

Staying Dry and Comfortable: How to Pack for Vietnam’s Humidity

Prioritize high-performance synthetic fabrics or linen over cotton to manage moisture and airflow. Pack half the clothes you think you need, as local laundry services are ubiquitous, cheap, and can turn around a load in 24 hours.

Select moisture-wicking materials. Avoid heavy denim and 100% thick cotton. Choose 'technical' fabrics like polyester-spandex blends or lightweight linen. These materials pull sweat away from your skin and dry within hours if washed.
Utilize a rolling method for packing. Roll your clothes tightly to save space and reduce wrinkles. Use packing cubes to separate 'clean' from 'worn' items; the humidity makes re-wearing damp clothes feel unpleasant, so keep them contained.
Plan for daily laundering. Don't pack for your entire trip. Bring 5-7 days of outfits and plan to use 'giặt ủi' (laundry) shops. They charge by weight, usually costing about $1.50 per kilogram. Drop your clothes off in the morning and pick them up the next day.
Pack a 'humidity survival' layer. Carry a lightweight, breathable shell or a thin long-sleeve 'sun shirt.' This protects you from the intense midday sun without trapping heat like a heavy jacket would.

Will my clothes mold in my bag?: If you leave damp clothes in a closed bag for more than 24 hours, yes. Always use a mesh laundry bag or a dedicated pocket for worn items to allow airflow until they can be washed.
Is it better to buy clothes there?: Yes. If you find yourself struggling with the heat, buy local, lightweight linen trousers or loose-fitting shirts in the markets. They are designed for the climate and are very inexpensive.
Should I bring a rain jacket?: Only if you are traveling during the rainy season. Otherwise, a thin, packable poncho is sufficient. Heavy waterproof jackets will just trap sweat and make you wetter from the inside out.