no built-in way to see how hot your Mac is
updated · by Anton Shakirov
on an Apple silicon Mac there is no temperature anywhere in the interface — not in Activity Monitor, not in System Information, not in Settings. the Terminal recipes you will find were written for Intel Macs, and on an M-series machine they do not fail quietly: they are refused. but there is one thing the system will tell you for free, and almost nobody mentions it.
what a Mac shows instead of cpu temperature
why the powermetrics command does not work
the recipe everyone copies is `sudo powermetrics --samplers smc`. on this machine it does not even get as far as asking for a password:
- powermetrics --samplers smc → «powermetrics: unrecognized sampler: smc». the sampler does not exist on Apple silicon; it was an Intel thing.
- sysctl -a | grep -c therm → 0. not a single key.
- ioreg does list the sensors — dozens of them, named PMU tdie and NAND CH0 temp — and exposes no values for any of them. reading those takes private framework calls, not a command.
so the honest statement is stronger than «there is no built-in readout»: the numbers are not merely hidden from the interface, they are not available to a command line either, under sudo or otherwise.
which is why most people end up diagnosing heat by ear, and that has its own trap — the fan is not reacting to what you are doing now: why your Mac fan is loud
check thermal pressure without installing anything
here is the part missing from every page in the search results. macOS publishes a thermal pressure level, and any user can read it, with no sudo and no app:
- notifyutil -g com.apple.system.thermalpressurelevel
- read the number at the end of the line: 0 is nominal.
- the scale is named in OSThermalNotification.h, which ships with the Command Line Tools: nominal, moderate, heavy, trapping, sleeping.
this is not a temperature, and that is deliberate on Apple's part: what an application is told is a state, not a number of degrees. for the practical question — «is this machine under thermal stress right now» — it is the correct answer and it costs nothing.
what it does not give you is history, a warning, or any sense of trend. it is a single reading you have to go and ask for.
the same idea in the form applications see it, which is why no app can show you a «real» number either: ProcessInfo.ThermalState
the one temperature macOS will tell you
the battery. `ioreg -rc AppleSmartBattery | grep Temperature` returns a value in hundredths of a degree — 3091 means 30.91 °C. it is a genuine sensor and it is genuinely readable, and it tells you about the battery rather than the chip.
and `pmset -g therm` exists, but on Apple silicon at idle it reports three lines of «no thermal warning level has been recorded». it fills in after a thermal event rather than describing the present.
macOS does the same thing one floor down with memory: it reports a state rather than a number, and for the same reason — what memory pressure actually measures
how hop shows cpu and gpu temperature
the free answer above is real and worth using: for «am I overheating right now», one command settles it. what it cannot do is tell you by how much, whether it has been climbing, or notice on your behalf.
hop's monitor keeps cpu and gpu load with their temperatures in the panel, alongside memory, network, disk, battery health and cycles, power draw and uptime. it is calm by default: values light up only when they leave the range you have set as normal.
| what you want to know | built into macOS | with hop |
|---|---|---|
| am I thermally stressed right now | notifyutil, one line, free | not needed for this alone |
| how hot the cpu and gpu actually are | not available — no command, no sudo, no ioreg value | shown in degrees in the panel |
| is it climbing or was that one spike | no history in any built-in tool | the last hour as a graph |
| tell me without my asking | nothing to notice on your behalf | warning on the menu bar icon |
| what counts as normal for this machine | no thresholds to set | you set them |
| did it throttle earlier | pmset -g therm — «not recorded» at idle | visible as a dip on the graph |
the first row is the honest one: if the question is binary, the command answers it and nothing needs installing. everything below it is where the built-in route has nothing at all.
the module in full, including what it watches besides temperature: system monitor on the features page
how to read a Mac cpu temperature once you have one
at what temperature does an Apple silicon Mac throttle?
- idle sits somewhere around 30–45 °C on most Apple silicon Macs; under a real load, 90–100 °C is normal and not a fault. these chips are designed to run there and to slow themselves down before anything is at risk.
- a high number on its own is therefore not a diagnosis. what matters is high while nothing is running, or high for long enough that the machine is visibly slower than it was.
- a fanless MacBook Air throttles instead of getting loud. the sign is not noise, it is the machine gradually becoming less responsive during a long job.
- temperature follows load by a minute or two. a spike during an export tells you nothing; a plateau all afternoon tells you something.
- the case being warm is a different measurement from the die. an aluminium body moves heat outward on purpose, and that is it working.
this is a pattern on macOS rather than an oversight: the system measures a great deal and shows almost none of it, and the speed test is the same story with a happier ending — the speed test already on your Mac
the only temperature Apple actually publishes is the room you are in — 10 to 35 °C — which is worth knowing when a page quotes a «safe» chip figure: operating temperature of Apple products
why the industry moved from degrees to pressure levels, if you want the reasoning rather than the numbers: power and thermal management on Apple silicon
when a hot Mac is a real problem, not just a high temperature
- it is hot with nothing open. find the process in Activity Monitor's CPU tab — an indexer, a sync client, an update, or something stuck in a loop.
- it started after a major upgrade and has not stopped. Spotlight reindexing takes hours and is supposed to end; days later is a different matter.
- the vents are blocked, or it is on a bed. the machine is doing its job and the heat has nowhere to go.
- the fan is loud at a constant speed while the load is low. that is a sensor or fan fault rather than a thermal one, and it is a service question.
- you are watching the number all day. this is the real risk of having a readout at all: these chips are meant to get hot, and worrying about it costs more than it saves.
the worst case for heat is a Mac held awake inside a closed bag, and that is easier to do by accident than it sounds: keep a MacBook awake with the lid closed
and if the machine is slow rather than hot, the number to look at is a different one entirely: «your system has run out of application memory»
frequently asked questions
- how do i check cpu temperature on an M1 or M2 Mac?
- not with anything built in. macOS shows no temperature on Apple silicon, and the command line has none either — the sensors appear in ioreg without values, and reading them takes private framework calls. it takes an app.
- why doesn't the powermetrics command work?
- the sampler it asks for does not exist on Apple silicon. `powermetrics --samplers smc` answers «unrecognized sampler: smc» — it was an Intel facility, and the recipes quoting it were written for Intel Macs.
- can i check if my Mac is overheating without an app?
- yes: notifyutil -g com.apple.system.thermalpressurelevel. no sudo, no install. 0 is nominal, and the levels above it are moderate, heavy, trapping and sleeping. it is a state rather than a temperature.
- what is a normal temperature for a Mac?
- roughly 30–45 °C idle, and 90–100 °C under sustained load is expected rather than alarming. Apple publishes an operating range for the room — 10 to 35 °C — but no figure for the chip.
- does a hot Mac damage the battery?
- sustained heat ages a battery faster, which is why running hot in a bag is worse than running hot on a desk. occasional peaks during heavy work are what the machine is built for.
- does Activity Monitor show temperature?
- no. it shows load, memory, energy impact and network, and no thermal readings on any Mac.
the tool behind this
system monitorload, temperatures, memory and battery — quiet until something is wrong.done with system monitor
other things people do
about the author
Anton Shakirovmakes hop
makes hop and every page on this site. eighteen tools under a single menu bar icon, MIT licensed and open source. reads and answers issues and email himself.