Glenn, thank you for your answer! I did the change and moved those lines to weewx.conf, then I restarted Weewx. But this doesn't change the values unit. It's still in US unit (F). I hope that it was clear that I meant the values, not the labels.
I looked at the section How options work in the Customizing Guide that TK pointed at but I can't figure out if that could help me... I feel that it is a little too advanced for me at this point. This is how it looks in weewx.conf after the change. [[wxobs]] HTML_ROOT = /var/www/html/weewx/wxobs skin = wxobs report_timing = 0 * * * * [[[Units]]] [[[[Groups]]]] group_rain = mm group_temperature = degree_C group_speed = km_per_hour What else can I provide to get help to sort this out? /Mikael -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/3fe91512-4cc9-4fa5-b58a-b1abb45bd8c1o%40googlegroups.com.