I did actually try -f and -fn, but with no luck.

Here's the rest of the socket info if you want to give it a test:
alias weathersock {
set %query $1-
if ($sock(weather)) { sockclose weather }
sockopen weather api.openweathermap.org 80
}
on *:sockopen:weather: {
sockwrite -n $sockname GET /data/2.5/weather?q= $+ %query $+ &appid=fac434f677376d8589d3db1a1831a201&units= $+ %forecast.type $+ &mode=html HTTP/1.0
sockwrite -n $sockname Host: api.openweathermap.org
sockwrite -n $sockname $crlf $+ $crlf
}
I'll replace the api key in a day or so, but for now that key can be used to test it. %forecast.type would be metric or imperial. The mode at the end is either XML, HTML, or JSON. %query would be, for example: Paris,FR