Hands on: Watch the temperatures of your MacBook Pro with iStat Menus 6

You've had this: your Mac is suddenly really slow and you can't figure out why. Most of the time this passes, much of the time it's just because macOS is doing some serious updating in the background. If the Mac speeds up again then we're all busy, we might uncross our fingers but typically we forget about it and carry on. The newly updated iStat Menus 6.20 is definitely for when it fails to speed up again — and we recommend having it all the time.

This is a power tool and we won't even pretend that we always understand the correlations of every statistic, every figure, or every detail of the stupendously comprehensive information iStat Menus 6.20 gives us. Then if you suspect your Mac is running hot, don't bother touching the case with your hand: get iStat Menus to tell you the precise temperature of each core. If you like, it will switch on your Mac's fans or rev them up according to your wishes.

Or for those times when you need to know the voltage being used by your RAM, there are few other options to check it.

Even if there is, though, even if you work at Apple itself and have all the thermometers you need, iStat Menus 6.20 is a supremely well designed app. We truly lost count trying to figure out how many different statistics it reports on but this mass of data is displayed remarkably clearly.

You can get a snapshot of the current data for any element iStat Menus covers by checking the main app.

This has all been streamlined and made slicker since the previous version but still, you're unlikely to spend much time in it. Instead, you'll pick the information you want from it and tell iStat Menus to display this in your menubar.

There are eight separate elements to iStat Menus ranging from CPU activity to Memory. You can separately switch on each of the eight and have them as their own menubar item. Then click on any to get a drop down menu of live, up to date, in-depth detail.

More useful, though, is a ninth option called Combined. This is a single menu bar item but you can tell it to include any or all of the other eight options. That doesn't sound like a big difference: either way you're getting eight menu bar items. What Combined does, though, is provide one menubar dropdown that has all the information you want in it.

Rather than either having all eight taking up room in your menubar all of the time, you can have one Combined icon. Or if you're particularly interested in certain things, let them have their own menubar icon and put the rest under Combined.

It's far from impossible that you'll switch them all off and have no menubar items at all. You wouldn't then learn anything at all about your Mac but when it's running fine, you may not care. So you can switch them on and off at any time and in any order.

You can now with version 6 have iStat Menus as a Today widget.

We like this app and sometimes we're agog at just how much detail it has. However, it won't fix anything: it only as good as you are. If you're technical enough to make use of its information then this is a powerful and essential tool. Even in mild general usage, it regularly provides the data that helps us solve a problem.

We typically have the Combined menu bar icon show us CPU, disk, memory and network activity. If our Mac is slow then a glance will tell us that the CPU is maxing out or the drive is full. It's basic information but we can act on it: clear some drive space, check which app is stressing out the CPU and so on.

You're going to find that there some iStat Menus items that are particularly useful to you and some that aren't. Hand on heart, we never expected to ever even glance at the new weather report option.

Weather

A Mac diagnostic tool adding a weather report sounded like Photoshop adding a spreadsheet or Word adding a fridge magnet. Yet now it's here and we've used it, we are startled to say that it could be our absolute favorite feature of iStat Menus.

That could be because we've just been through some unusually hot weather and kept checking in the hope of rain.

However, it's really more that this weather report is presented with the same detail and design flair. It looks great, it's easily one of the clearest and most comprehensive weather apps we've seen — and it's available at a keystroke.

It's really only the Combined menubar option that you can set a keystroke for and we did hit an oddity with Weather. If we had it in the Combined view then sometimes whether or not we had any other items, we'd get a notice about updating instead of the full weather report.

Take it out of Combined and just use it by itself and it never failed to show us detail. It also never failed to have us go from just a quick glance into scrolling further and further through its information.

Why is it there in a Mac troubleshooting app beyond just "because it can be?" Because sometimes, humidity, pressure, and temperature can play a part in identifying a strange, rare failure. Especially if you've got a flaky hard drive that only acts up sometimes.

We'll find out just how much we like this over time because after an initial period, the weather in iStat Menus is an extra paid service. The developer says that you typically get many months as part of your purchase price but there isn't one specific limit. You can see what time you've got when you click on the Weather button.

In our case, it's a year's worth of free data. In all cases, after the free period is up, the developer charges from $2.49 per year for the data. There are three price tiers, each giving you a year but varying in how often that weather data is updated. For the $2.49 it's refreshed every hour where for the top $8.39 tier it's every 15 minutes.

See what you think by downloading the free trial of the app. It's really of most use when there's something wrong with your Mac but when that's happening, you don't have time to play with options. So get it now, see all it can do, enjoy the weather feature in particular, and then keep it as a tool for your future troubleshooting.

You can get iStat Menus 6.20 direct from the developer or as as part of Setapp, the app subscription service that we previously examined that charges $9.99 per month for a pile of apps. The Setapp version only installs for the current user where the direct one does for every user on a given Mac.

Then there is also a slightly constrained version from the Mac App Store that lacks the weather and some statistics information. Both it and the developer's direct version cost $17.99 and require macOS 10.11 or higher.