Install wmtemp by entering the following commands in the terminal:
sudo apt update sudo apt install wmtemp
Description:
WM dock applet displaying lm_sensors temperature values
Nifty small dock applet for Window Maker that continuously displays CPU and case temperature by virtue of lm_sensors
Homepage: http://gnodde.org/wmtemp/
Version: 0.0.6-3.3build1
Section: universe/x11