So... we're talking about regional warming, not global warming, right?
As I said, most climatological data sets show that the warmest decade of the 20th century was the 1990s. The 1930s were the next-highest. It cooled off a bit in the 1960s and 1970s. If a couple of spots were a tad bit warmer in the 1930s than the 1990s, that doesn't affect the statement that in general over most of the globe, the 1990s were warmer than the 1930s.
And if you will look at the graph in an earlier post, you will also see that the planet has warmed more rapidly since the 1980s than the warming into the 1930s. That's significant, too.