A change that seems minor to an adult can remove the part of the day a child was looking forward to. Before presenting the replacement plan, explain what has changed in a few clear words. The playground is closed today tells the child more than plans change, deal with it.
Say what is known and avoid adding a reassuring promise you may not be able to keep. If you do not know when an activity can happen again, say so. We will look at another day is different from promising tomorrow while the closure remains uncertain.
Let the feeling exist beside the new plan
The child can be disappointed even when the reason for the change is reasonable. Acknowledge the lost expectation without requiring immediate enthusiasm for the alternative. You really wanted to see your friend can be enough; a long explanation about how much effort adults made may add guilt rather than clarity.
Offer a limited choice if there is a real one. We can go to the library or head home for a game gives a manageable decision. If the family must go home, state that boundary and offer a smaller choice there. Do not present the necessary destination as optional and then argue with the answer.
For a younger child, describe the next action rather than the whole revised afternoon. For an older child, explain which parts remain unchanged and invite a suggestion that fits the actual limits. A replacement does not have to match the original in cost or excitement to be worthwhile.
Return to the conversation later if needed
If the change occurs during travel or another busy moment, handle the immediate situation first. Later, ask what was hardest about it. You may discover that the concern was missing a friend, not the venue, or uncertainty about what would happen next.
Avoid turning every change into a lesson about gratitude or flexibility. Children learn from seeing adults adjust too, including hearing a calm admission that you are disappointed as well. The aim is to help the child understand the new situation and move through it with support, not to make them declare that the canceled plan no longer matters.