Hi! Sorry for my so late reply !
I confirm @siim statement: after disabling ublock, the red message is gone.
And ublock reports this url in its log: https://node.windy.com/node/geoip?source=testConnection
geoip is highlighted in red in ublock logs, so I guess this is the trigger.
It's not critical for my personnal use, I can just disable ublock for my page.
But in a general way, it may be a good idea to modify this keyword as suggested by @siim
For reference if needed:
uBlock Origin v1.18.16
Firefox 66.0.3
site: http://meteosaintsulpice.fr/