Is there another way ?
Package hddtemp is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'hddtemp' has no installation candidate
~/Downloads$ sudo apt install sensors
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
E: Unable to locate package sensors
hddtemp is no longer being incorporated into Ubuntu per this at Launchpad build versioning.
The replacement is the "smartctl" utility, using the command:
smartctl -a /dev/sda | grep "Temperature"
That is part of the "smartmontools" package.
If your drive does not support SMART, then you will need to build the hddtemp package.
It did not find Temperature.
194 Temperature_Celsius 0x0022 120 105 000 Old_age Always - 32
196 Reallocated_Event_Count 0x0032
smartctl -a /dev/sda | grep "Temperature_" does not work either.
I want to display the hard drive temp in Fahrenheit. Searching the help info did not find "Fahrenheit"
I wonder why hddtemp was moved to the curb?
This seems pretty good. It is in SPM. (synaptic package manager.)
Their website, but all I get is Problem loading page.
According to the GitHub project for psensor, that project appears to have been static for 10 years.
"sensors" is the command-line equivalent that provides the temperatures, with extras. (lm-sensors package)
sensors -f
atk0110-acpi-0
Adapter: ACPI interface
Vcore Voltage: 1.24 V (min = +0.85 V, max = +1.70 V)
+3.3 Voltage: 3.46 V (min = +2.97 V, max = +3.63 V)
+5 Voltage: 5.11 V (min = +4.50 V, max = +5.50 V)
+12 Voltage: 12.42 V (min = +10.20 V, max = +13.80 V)
CPU FAN Speed: 4500 RPM (min = 600 RPM, max = 7200 RPM)
CHASSIS FAN Speed: 0 RPM (min = 600 RPM, max = 7200 RPM)
CHASSIS FAN 2 Speed: 0 RPM (min = 600 RPM, max = 7200 RPM)
CPU Temperature: +140.0°F (high = +140.0°F, crit = +203.0°F)
MB Temperature: +120.2°F (high = +113.0°F, crit = +167.0°F)
Using it without the "-f" option reports for default, Celcius.
There is also the "mate-sensors-applet" which you can get from right-click on panel.
The "kicked to the curb" program had the ability to compensate for errors.
Some of the hard drive info is approximate.
The temps showing are about what the inside of my refrigerator is. 
sensors -f
radeon-pci-0008
Adapter: PCI adapter
temp1: +46.4°F (crit = +248.0°F, hyst = +194.0°F)
fam15h_power-pci-00c4
Adapter: PCI adapter
power1: N/A (crit = 65.19 W)
k10temp-pci-00c3
Adapter: PCI adapter
temp1: +42.8°F (high = +158.0°F)
(crit = +176.0°F, hyst = +174.2°F)
I used that "forgot the name program" only about 2 years ago.
I am a recovering perfectionist.
This was an excellent program. Bummer.
lm_sensors[dead link 2024-10-12 ⓘ] (Linux monitoring sensors) is a free and open-source application that provides tools and drivers for monitoring temperatures, voltage, and fans. This document explains how to install, configure, and use lm_sensors.
According to Launchpad, "lm-sensors" is still included as an option for the Ubuntu distro.
There is also this Nagios-originating package for a set of different tools, if you are ready to experiment:
As for the mate-sensors-applet, I posted elsewhere about that earlier.