Name the family movement
A destination alone does not say whether your child will be walking, in a carrier, in a stroller, in a car seat, or taking part in an activity. Those details change exposure, spare-clothing needs, and how easy it is to adjust layers.
Start with the leg of the trip that will feel most constrained. A long car transfer, a windy ferry deck, a wet trail, or a crowded indoor venue each needs a different kind of backup plan.
Use a packing list as a review tool
A list is most useful when every entry has a reason: keep dry, change after water play, cover a transfer, or handle a cooler return. Remove items that do not have a role rather than turning the list into a general shopping prompt.
Weather changes and local advisories can alter the plan. Review the day-of forecast in the mobile app, and use transportation, activity, and venue instructions as the final authority for the outing.