Core Temp lists a temperature for every core the processor actually exposes, plus the CPU fields around that reading. This page walks through those parts. The Windows copy is version 1.21, dated 3 October 2026.
The main window is a processor report, not a list of board sensors. It shows the model, socket, frequency, multiplier, VID, revision, lithography, CPUID, and TDP. Under that, each core has the current temperature, the minimum, the maximum, and the load. Tj. Max stays on screen so you can see how close a core is to the junction limit the vendor set.
Core i7-2600K, four cores, eight threads, 4298 MHz, VID 1.3661 V, 32 nm, TDP 95 W. Core 2 reached 65°C. Choose the image to view it larger.
On Ryzen, the same window can show Tdie and Tccd next to the cores. The home page image of a Ryzen 9 9950X (Granite Ridge, 16 cores, 4 nm, TDP 170 W) has Tj. Max at 95°C, Tdie at 47°C, and cores between 26°C and 30°C at 2% load. Those are separate sensors. One package number would hide that gap.
Version 1.19.5 added readings per CCD and per core for most Zen models, including Zen 4 and Zen 5 desktop and laptop parts and Threadripper 7000 and 9000. It also added an effective clock, a core picker for frequency, and P-core / E-core tooltips on Intel hybrid chips.
How the number is worked out
The reading does not come from a diode on the motherboard. Intel, AMD, and VIA publish different registers. Core Temp follows those methods. A question mark after a value means that sample was not marked valid. Some 45 nm Core 2 chips do not report temperatures below about 30°C or 40°C.
The published temperature math Core Temp follows.
Processor
What is read
Temperature
Intel, from Core 2 onward
Tjunction, then a delta in a model-specific register. From Nehalem, Tj. Max itself can be read. The delta field is 7 bits, so the theoretical range is 0 to 127°C.
Tj. Max minus that delta
AMD K8 (Athlon 64, early Opteron, Sempron)
A register in the CPU northbridge, then the formula AMD published for that generation.
The register value minus 49
AMD K10 and many later package sensors
Phenom, Phenom II, and related Opteron parts often expose one sensor for the processor, not one for each core.
The register value divided by 8
AMD Zen
Current builds add readings per CCD and, on most models, per core, plus TDP and Tj. Max detection on most Zen parts.
Shown for each CCD and each core when the model supports it
VIA
An absolute Celsius value from the core sensor. There is no conversion step. Tj. Max is usually 70°C on desktop parts and 90°C on mobile and low-power parts.
The sensor value, in Celsius
The log and the grapher
Logging can be turned on and off, with one interval for reading temperatures and another for writing the log. The file is plain text meant to be opened in a spreadsheet. Version 1.21 fixes a custom log path that was not applied when the program started. Overheat-protection events can also be written to the Windows Event Log.
Core Temp Grapher is a separate add-on, either a plugin DLL or a standalone exe. It draws load and temperature for each core. The image below is the older sidebar gadget on a Core i3-540: clock, Tj. Max, RAM, two core bars, and a small history graph.
Gadget view: Core i3-540, 1604 MHz, Tj. Max 105°C, core 0 at 33°C / 16%, core 1 at 36°C / 11%, RAM 2784 of 7864 MB. Choose the image to view it larger.
The Windows 7 sidebar gadget and the Windows Media Center add-on are older companions for Vista and Windows 7. They need Core Temp to be running. They are not included in the 1.21 installer.
The notification tray
Temperatures can stay in the Windows notification area so the main window does not have to stay open. Version 1.21 rebuilds the tray configuration dialog and corrects missing icons and their order. The same build lets the Logitech G15 applet show up to 10 lines in the built-in font when the date and time line is turned off.
Protection from overheating
You can set a temperature that triggers a warning, hibernation, or shutdown. The warning can be turned off. Version 1.21 makes the overheat message the top-most window so a full-screen job does not hide it. If nobody is at the PC, hibernation or shutdown is the action that matters. Use the overheat guide if the warning repeats on every sample.
Plugins and shared memory
Plugins and other programs share one data layout. The current structure version is 2. Later versions are meant to extend it without breaking older readers. Temperatures follow the Fahrenheit switch and the switch for distance to Tj. Max. TDP and power arrays are valid only when their flags say so.
Fields other programs can read from the shared memory Core Temp publishes.
Field
What it holds
Temperature for each core
Up to 256 temperature values
Load for each core
Load percentage for every core
Tj. Max and TDP
For each processor, when the chip reports them
Frequency
CPU speed, FSB or reference clock, and multiplier, including a multiplier for each core
VID and power
VID, plus power when the power flag is set
Name and scale
CPU name, core count, CPU count, Fahrenheit flag, and the flag for delta to Tj. Max
People have reported that older plugins are less reliable on the 64-bit build. If a plugin does not load, use the plugin guide before you replace Core Temp.
Remote and gadget views
A network plugin can publish the same processor status to another program. That is how the phone-style monitor works: machine name, online or not, model, clock, VID, Tj. Max, and a bar for each core. The image below is an Intel Core i3-540 (Clarkdale) at about 1203 MHz, with core 0 at 37°C / 17% and core 1 at 39°C / 21%.
Remote status for a machine named Main. Choose the image to view it larger.
Dark mode in the main program needs Windows 10 or newer. It does not restyle every old dialog. If a language file does not change the menus, the language guide is the next place to look.
Core Temp