If the flight is cancelled due to weather, can the "return ticket" be refunded or changed?

Ordinary tickets can be refunded or changed as long as they are not special tickets marked non-refundable.

Did you buy a round-trip ticket or separate tickets?

For round-trip connecting flights, the previous flights are involuntarily cancelled, and for return flights, airlines can refund or change their tickets accordingly.

If you buy them separately, the journey and the return trip will have nothing to do.

Different airlines have different fare regulations for different discounts. Please consult the airlines for details.