It would be best to use xfce4-weather-plugin. It can be compiled.
Download latest version
You must have:
sudo eopkg install -c system.devel
sudo eopkg it xfce4-panel-devel libsoup-devel libxfce4util-devel libxfce4ui-devel json-c-devel libgtk-3-devel
Unzip the downloaded package and go to the catalog
Compile/install:
./configure --prefix=/usr
make
sudo make install
If something is missing, write.