Hi Will,
It seems your weatherstyle.css file is missing on your website !
I suppose you have installed the new software version including the new (blank) HTML templates.
If this is exact, please copy the content of the web directory from the backup you have done prior to new installation, following Kerry's advice, in the new Cumulus web directory.
Regards,
Marcel
In the future, for each new Cumulus upgrade, you will need to clear (untick? uncheck?) the HTML templates.