RPI4 Ubuntu 19.10 64bit Temperature Monitoring

Without sensors command this has worked on many Ubuntu distributions for me:

$ paste <(cat /sys/class/thermal/thermal_zone*/type) <(cat /sys/class/thermal/thermal_zone*/temp) | column -s $'\t' -t | sed 's/\(.\)..$/.\1°C/'

INT3400 Thermal  20.0°C
SEN1             57.0°C
B0D4             54.0°C
SEN2             54.0°C
SEN3             60.0°C
SEN4             65.0°C
pch_skylake      85.5°C
x86_pkg_temp     55.0°C

Note pch_skylake temperature has always been wonky on my system.

You may use landscape-sysinfo, which should come pre-installed on Ubuntu Server:

$ landscape-sysinfo
  System load:  1.48              Temperature:           66.7 C
  Usage of /:   8.9% of 27.91GB   Processes:             134
  Memory usage: 7%                Users logged in:       1
  Swap usage:   0%                IPv4 address for eth0: 192.168.1.191

It automatically runs as part of the default MOTD (message of the day) script that runs when you ssh.