I think my Mac Mini 2018 Runs hot. Apple will not give me any numbers for a reference.

Run the Apple Diagnostics to make sure the cooling system if functioning correctly. This is one area where the diagnostic results are fairly reliable even for a passing result.

The later Intel CPUs will run much hotter than older Mac models and is normal. At idle the recent Intel CPUs will hover around 35C to 45C depending on what is launched during boot & login. As soon as you do anything (even opening a folder), you may see the CPU temp spike to 80C for a moment because as soon as a core on an Intel CPU is accessed, the temp increases drastically & immediately since there are no special lower power mode cores to do the simple tasks. The more & longer the core(s) are used, the hotter the system will get. I haven't had the opportunity to monitor the Intel Mac Mini 2018 model, but on the laptops, the CPU temps will generally hover between 65C - 80C during average workloads and stay at 90C-95C for more intense workloads.

If you are not doing anything on the computer, yet you have high CPU temps, then you most likely have some sort of software issue, most likely with some third party app. You can use EtreCheck and post the report here using the "Additional Text" icon which looks like a piece of paper. Forum contributors can examine the report to see whether we notice any thing which may contribute to higher system temps.

You can also try disconnecting external devices in case one of them is causing a problem.

Edit: Added link to the EtreCheck app. FYI, it is better to post temperatures in Celsius because most of the tech reviews and benchmarks display the temps in Celsius so it is easier to compare results. All of my own tests have been using Celsius, even though everything else in my region utilizes the Fahrenheit scale.

Using iStat Menus at the moment to see what my 2018 reads. Right now, with just Safari and Mail open, it's hovering around 120º. Current readout of all component temps:

This is typical when the Mini isn't under load, such as intense Photoshop work or rendering in DaVinci Resolve.

Do you have enough clear space around the Mini for heat to properly dissipate? Do you have anything sitting on top of the Mini? Doing so only serves to trap heat. Is it sitting on a soft surface that doesn't allow heat to radiate out from underneath?

You also shouldn't use any type of secondary fan control. Only Apple's engineers know what the proper thermals of your Mac should be, which is built into the both the hardware and software. The users should never try to assume they know more about their Mac than Apple does.

Yeah’ it could have some dust buildup inside. To check, shutdown, unplug, pop off the bottom and check. If you are not comfortable doing that, take it to your local AASP for service.

Try a different well ventilated location first.

Then go back to those MacFanControl settings, before wasting any money on an additional cooler.

What App(s) are causing your 2018 Mac mini to run warm?

I consider 100-150F normal, 160-170F warm, 180-190F hot and 200F + toast.

Right now my 2018 Mac mini is just idling with Safari, Music and a few other light app's running.

If Apple engineers are so smart then why do we need a second party app to measure Temps?

Need? You don't need one at all. The Mac takes care of itself.

Thanks by the way I am downloading it!

Go ahead. No one said you couldn't. I said the user shouldn't be trying to control the fans.

Why wait until it is so hot you are having problems?

If any Mac (or iPhone or iPad) gets that hot, it will automatically shut down to prevent damage.

The fans will run at whatever speed is necessary without the need for the user to intervene. As far as how much heat is generated on average, it all depends on what you having running. den.thed's is lower than mine for the very likely reason s/he doesn't have as many background items running. I have a lot, and they're all necessary for the software I use. About half of those listed are not loaded unless the main associated app is also running. But it's still quite a bit more than many users.

That looks pretty normal. At least to me it does. It's slightly higher than my "at rest" temp, but not by much. Just launching Photoshop causes the temps to hit 160º for a moment. But the fans still don't increase in speed until I really start pushing more involved processing at it.

You’re welcome. Also keep in mind, that there is a thin air gap around the bottom cover for cool air intake.