This widget has been known for hiccups connecting to (apparently) Yahoo servers to fetch data. However in the last few months this behavior, while random, became more frequent. During one of such hiccups I posted to their public "User Voice" suggestions desk which I highly doubted would make difference, however the widget started showing the weather again and then it abruptly stopped doing that.. once more and there has been nothing for a few days in a row now. The widget doesn't display weather in any macOS I run from Lion to High Sierra.
I say: corporations, remove features in your new products but why make life harder for those who're on the older versions? This is unacceptable and dirty.