Search for how to check your Mac’s temperature and you’ll find the same command copied across years of guides: sudo powermetrics --samplers smc. On an Apple Silicon Mac it doesn’t work. Here’s what does, tested on an M2 Max MacBook Pro running macOS 27.
Why the old command fails
powermetrics is a real Apple tool, but on Apple Silicon it has no smc sampler. Run powermetrics -h and the list of samplers includes cpu_power, gpu_power, and thermal, but not smc. That sampler only existed on Intel Macs, which is where those guides came from.
What the built-in tools can tell you
macOS doesn’t show temperatures in Activity Monitor or System Settings. What it does expose is thermal pressure: whether the system is under enough heat stress to start limiting performance.
powermetrics --samplers thermal
sudo powermetrics --samplers thermal -n 1This prints the current thermal pressure level, such as Nominal. It doesn’t give degrees, but it answers the question you usually care about: is my Mac hot enough to slow down?
pmset -g therm
pmset -g thermNo administrator password needed. On a Mac that hasn’t hit thermal limits, it reports that no thermal warning level has been recorded. If you see a performance warning here during heavy work, the Mac was throttling.
How to see actual temperatures
To read degrees, you need an app that reads the Mac’s sensors directly. Apple doesn’t document the sensor names, and they differ between chip generations, so these apps maintain their own mappings.
With FanBar, which is free and open source:
- Download the latest release and open it. It lives in the menu bar.
- Click the menu-bar item. The popover shows CPU, GPU, SSD, and battery temperatures with a ten-minute history chart, alongside each fan’s speed.
- To keep a temperature visible at all times, choose what the menu-bar item shows in Settings → Appearance.
Reading temperatures needs no special permission. FanBar only asks for administrator approval if you later choose to control the fans yourself, and you can see exactly what that permission allows.
Other options exist: Stats is a free, open-source system monitor, and TG Pro and iStat Menus are paid apps with broader features. We compare them in Macs Fan Control alternatives.
What the numbers mean
Temperatures depend on the chip, the workload, and the room, so treat any single number with caution. For reference, here’s one of our own readings from a 16-inch MacBook Pro with M2 Max during light use (browser, editor, chat):
| Sensor | Reading |
|---|---|
| CPU | 54 °C |
| GPU | 51 °C |
| SSD | 32 °C |
| Battery | 31 °C |
Some general guidance:
- CPU and GPU rise quickly under load and fall quickly after. High readings during an export, a game, or a compile are expected. Apple Silicon is designed to run hot under sustained work, and macOS slows the chip down before heat becomes harmful.
- The trend matters more than the peak. A chip that’s hot while idle points to a background process; check Activity Monitor.
- Battery temperature moves slowly and is worth watching while charging. Sustained heat is hard on battery health over time.
- SSD temperature mostly tracks long file transfers and the temperature inside the case.
If thermal pressure regularly leaves Nominal during work you care about, raising the fan speed before the heavy task can help the Mac hold its performance. That’s the kind of control FanBar adds on top of monitoring, within each fan’s hardware limits.
FAQ
Can I check Mac CPU temperature without installing anything?
Not in degrees. Built-in tools (powermetrics --samplers thermal and pmset -g therm) report thermal pressure and thermal warnings, not temperatures.
Does Activity Monitor show temperature? No. It shows CPU, GPU, memory, energy, disk, and network usage, which helps you find the cause of heat, but not the temperature itself.
Why do different apps show different temperatures? Each app chooses which of the many sensors to show, and some average several of them. Compare trends within one app rather than exact numbers across apps.
Do I need to grant permissions to read temperatures? Not with FanBar. Monitoring works without approval; the privileged helper is only needed for fan control.