Cupping is caused by a difference between one side of a board and the other. Sometimes floors cup due to acclimation issues and stay cupped. The only possible real longevity would result from wear on the higher portion of each board. A floor that cups could be a sign of water intrusion or other moisture related issues.
Buckling is caused by overall board expansion causing enough pressure to lift the floor from it's adhesive or fasteners.
It sounds like your issue is normal and minor. I don't think you need to worry.

The simple solution is never open your windows ever again. (Kidding)

Is this cupping happening directly infront of the window? Perhaps where the sun is beating down on it?

Overall i agree thats its minor and you shouldnt worry. The only thing to keep in mind is if that particular area that cups gets a lot of traffic then that area will wear pretty fast thus causing black marks and worn finish.

Thank you both for replying. No, it happens all over the floor, not just in front of the windows. Glad to know it's probably nothing to worry about. Very reassuring!