macOS: -bash: warning: setlocale: LC_CTYPE: cannot change locale (UTF-8): No such file or directory

Source: nixCraft
Option #1 : Terminal > Preferences > Profiles

However, this may cause some issues with e.g. PostgreSQL psql displaying unicode characters, e.g. <e2><94><8c><e2><94><80>.
So, if the issue is only caused by ssh, I prefer option #2:

sudo vi /etc/ssh/ssh_config

#       SendEnv LANG LC_*