The classic shape, doing two jobs. A teardrop of natural cedar with a dial set into the face, reading both the temperature and the humidity of your room.

Why humidity matters as much as heat

Temperature alone does not tell you what a sauna feels like. A room at 80 degrees and 10% humidity is a completely different experience from the same room at 30%, and the second one is what people mean by good loyly. Reading both together is how you learn the combination your room gives at its best, and then aim for it.

Cedar, and why it lasts

An ordinary household gauge fails in a sauna. The heat and humidity a sauna runs at will warp a plastic housing and swell a poorly chosen wood. Cedar handles both, which is why the room is built from it, and the grain means the gauge reads as part of the wall rather than something screwed to it.

Dimensions

7 in high (18 cm), 5.5 in wide (14 cm), 1 in deep (2.5 cm). Wall-mounted.

Where to put it

Around upper bench height on a wall away from the heater. Directly above a heater any gauge reads hotter and drier than the air you are actually sitting in, and on the ceiling it reads the hottest layer in the room rather than a useful one.

Accuracy, honestly

A sauna is not one temperature or one humidity. There are hot and cold spots within a single small room, and a dial instrument is indicative rather than scientific. Use it to learn what your room does at its best, then aim for that.