Check Mac fan speed and temperature without Activity Monitor

The fans on your MacBook just ramped up to jet-engine territory, but Activity Monitor has no temperature column, no fan RPM, no thermal readout. macOS hides this stuff on purpose — Apple wants you to trust the firmware — and that’s fine until you actually want to know whether your CPU is at 70°C or 95°C right now.

Here’s how to get to it.

Two paths

The native way (Terminal)

There’s no GUI built into macOS for fan speed or core temperature. The closest thing is the thermal log:

pmset -g thermlog

That prints CPU thermal pressure events in real time — useful for catching throttling, but it only logs when something changes, and it gives you nominal/moderate/heavy levels, not actual degrees.

For raw sensor data you’d traditionally use powermetrics:

sudo powermetrics —samplers smc -i 1000 -n 5

That dumps CPU die temperature, fan RPM, and power draw every second for five samples. It works, but it needs sudo, the output is a wall of text, and it definitely isn’t ambient awareness.

The Beacon way

Beacon reads the SMC directly and puts thermals in the menu bar — temperature, fan RPM, or both, depending on what you care about.

1. Install Beacon and open the menu bar panel.
2. In Settings > Menu Bar, enable Temperature and/or Fans.
3. For temperature, pick the sensor — CPU die, GPU, or the hottest reading across the whole machine.
4. For fans, choose RPM or a percentage of max — most people prefer the percentage.
5. Click the readout to see all available sensors at once, including individual fan speeds on Intel Macs and the per-cluster CPU temps on Apple Silicon.

A note on hardware: silent MacBook Air models (M1, M2, M3) don’t have fans. Beacon will still show temperature on them, which is more useful — you can see when the chassis is heating up enough to throttle, even without a fan to warn you.

If you’ve ever been mid-render wondering “is it the laptop or is it the room”, a glance at the menu bar settles it.