Use wttr.in/Dubai?T to avoid all the escape codes that you’re seeing.
To see all the options, try wttr.in/:help
Also you might want to enclose the output in your template inside a code block. (i.e. put three back ticks on the line before <% tp.user.weathernow() %> and three back ticks on the line after). The output from wttr.in won’t look right if it’s not seen with a monospaced font.