So I was all set to condescend to someone who said they were coming up from Dallas to Austin, because Dallas is obviously north. But I thought I would protect myself by looking up the elevations of the two, and it turns out that Austin is officially 38 feet higher than Dallas. Serves me right.
You can look up elevations here, but it may be wrong if your city has risen or fallen since 1987. All you Houstonians are probably out of luck, since your city was built on a swamp.