City kanji = towel +lid radical; but separate city radikal?

Oh boy, I’ve completely misread OP question the first time.

Most of kanjis are not gonna make sense like tree or mountain. And most of them are build as semantic phonetic components. There is a great userscript that will show you details:

And bunch of threads discussing it, for example:

I’m on the phone, so cannot see the script right now, but it is very helpful in general. You can guess the reading when you recognize the phonetic part. And both sister and city reading is し.