Da Nang, Hue & the centre is in its storm season right now, September to November. Most trips are unaffected, but a storm reroutes flights and closes beaches at a day's notice — the packing consequence is a buffer day and a charged power bank, not different clothes.
Going in January
The wet season, and it is a serious one: October and November bring flooding that regularly closes Hoi An's old town.
What this means for your bag
A packable rain shell
Not a winter coat — it stays warm through the rain. A light hooded shell that folds into its own pocket ends up in the day bag instead of the hotel room.
See the Weather Protection packA dry bag or two
Phone, passport and camera in something sealed. A cheap roll-top bag also doubles as the wet-clothes bag on the way home.
See the Weather Protection packShoes that survive being soaked
Streets flood faster than they drain. Sandals or mesh trainers dry overnight; leather does not, and one wet pair means walking in wet shoes all week.
See the Active & Adventure 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 pack
Build a packing plan around the season you are actually travelling in.