Am alternative to the "MATE Weather" indicator I found very useful - provides almost any location and is not limited to the few available in "MATE Weather" => "Meteo" (got it from here: 5 Best Weather Apps for Ubuntu & Linux Mint - OMG! Ubuntu -> 2.Meteo)
How to install:
sudo add-apt-repository ppa:bitseater/ppa
sudo apt install com.gitlab.bitseater.meteo
After installation you can start the app directly from the menu (search for Meteo).
From the preferences you can choose:
- Use System Tray Indicator
- Start minimized
- Launch on start (or configure Meteo as a Startup application in the Control Center)