The wine-whine merger is a merger by which voiceless /hw/ is reduced to voiced /w/.
...
The merger is essentially complete in England, Wales, the West Indies, Australia, New Zealand, and South Africa, and is widespread in the United States and Canada.
...
According to Labov, Ash, and Boberg (2006: 49),[2] while there are regions of the U.S. (particularly in the Southeast) where speakers keeping the distinction are about as numerous as those having the merger, there are no regions where the preservation of the distinction is predominant. Throughout the U.S. and Canada, about 83% of respondents in the survey had the merger completely, while about 17% preserved at least some trace of the distinction.
...
While some
RP speakers still use /hw/, most accents of England, Wales, West Indies and the southern hemisphere have only /w/.