The monsoon is a delivery problem before it is a storage problem. Your stock sitting in damp air is one risk; a parcel sitting in it for four days is another, and the second one is the one a buyer sees.
What happens to parcels
Cardboard is the first thing to fail. A box that would be fine in March arrives soft, and a soft box is a crushed box. Water gets in at the seams and the tape, not through the walls.
Delays stack rather than being spread out. A blocked road is not slower delivery, it is a parcel that does not move at all for two days and then arrives with everything else.
What to change about packing
A plastic layer inside the box, around the item. Not instead of the box — inside it. The box takes the damp; the item should not be in contact with it.
Tape the seams, not just the join. Water finds the seams.
Double-box anything that cannot get wet — paper, textiles, anything with glue, anything electrical.
What to tell buyers before they order
Say the delivery may take longer, in the listing, in these months. A buyer who was told is a buyer waiting; a buyer who was not told is a buyer opening a dispute on day four.
If something genuinely should not travel in heavy rain, say that too, and say when you will post it. A buyer will nearly always rather wait than receive it ruined.
When collection is the better offer
This is the season for it. Collection removes the courier entirely, and for anything heavy, fragile or absorbent that is the whole risk gone. A buyer has 72 hours to collect once it is ready, unless you set your own, which is enough to work around a wet afternoon.
Offer it per item rather than across the store — the things that should not be posted in July are usually a specific few.
What not to do
Do not post and hope. A parcel you were uneasy about is the one that generates the return, and the return comes back through the same weather.
Do not shorten your dispatch window to look fast. Promising 24 hours in a week when you cannot reach the courier is a missed deadline you chose.
Questions people ask
Can I pause my store for the season?
You do not need to. Take the things that should not travel off sale and leave the rest.
Who pays if a parcel arrives water-damaged?
It is a faulty arrival, so it is returnable for 7 days whatever your own policy says. Packing for the season is cheaper than that.
Is local delivery safer than a courier?
Usually, because it is one journey and you control it.
More: monsoon and your stock, why some things cannot be posted, selling around festivals and seasons, packing collectibles.