FSS? This isn't America you know
ATC "should" be able to give you weather but often they are too busy, or they say they will get back and don't. You can't really rely on this. Also, ATC in much of southern Europe is sometimes barely able to speak English, get by on the few standard phrases, and reading off a Metar in anything resembling ICAO Level 0 English is beyond them.
Normally I use a Thuraya 7100 satellite phone (for an internet connection) to get weather, on long flights, but not everybody has one of those. However, one can use such a phone for SMS and that would be another useful tool because it does often fail to connect to the internet.