I am trying to include my website address in the address block of a letter.
My webaddress has a tilde character, and my usual solution, $\sim$, to the tilde formatting problem is not working.
The relevant code is
\documentclass[english]{letter}
...
\address{ Street \\ City, ST 00000 \\ \url{http://my.web.address/~blah} }
...
This gives a bad-looking top-aligned tilde.
If I replace ~ with $\sim$, then "http://my.web.address/$\sim$blah" appears in the output PDF. Using \texttildelow gives a compilation error.
Edit: This is not a duplicate. Solutions for the referenced questions do not work inside \address{}.

\address{}in the letter documentclass. – user1149913 Apr 26 '13 at 16:03