Ask HN: Where in the US are software salaries around or above national average?

I periodically look around on Glassdoor for software salaries around the country, and it seems like vanishingly few cities have software salaries at or above national average. SV salaries are well above, but NYC's are only 4% over. All of the other major cities I can think of are double-digits under. Are the software jobs really so concentrated in SV that it skews the whole national average so dramatically? Or are there other pockets as well?