Host key verification failed......
Remember weewx runs as user 'weewx' and not your typical user (in your case 'kevinphy')....
You need to ssh into the remote host as the user weewx runs as 'once', accept the remote host's system key when prompted, and weewx will be able to rsync over ssh as 'its' user. It can be a little convoluted to do this typically, so I usually cheat a little....
# temporarily let weewx run a shell
sudo chsh -s /bin/bash weewx
# su to the weewx account
su - weewx
(you will be in a shell as weewx)
# seed its known_hosts file and set permissions correctly
ssh your_remote_host_or_ip
(answer yes for the host key prompt, then ^C to exit)
(and exit your weewx shell)
# (re)set weewx's shell to nologin
sudo chsh -s /usr/sbin/nologin weewx
There is undoubtedly many ways to do it, but this worked for me.