Sauna Thermometers and Hygrometers

By Caleb Whitaker Prices checked November 12, 2026

Short answer

A sauna thermometer costs about $19 to $190. Most combine a thermometer with a hygrometer for humidity. Hang it on the wall opposite the heater, never above it, at the height where you sit. A traditional sauna typically reads about 150 to 195°F.

Prices

Sauna thermometers, lowest price first, read November 12, 2026
Brand	Model	Price seen	Type
Dundalk	Wood thermometer and hygrometer (with a Dundalk sauna only)	$19	Analog, wood, 7 x 5.5 in	Visit website
Touch of Finland	Chrome thermometer and hygrometer, 4 in	$49.99	Analog, metal face	Visit website
Narvi	Smoke flue thermometer (for wood stoves)	$59	Magnetic, reads the chimney pipe	Visit website
Dundalk	Wood thermometer and hygrometer	$66	Analog, wood	Visit website
Scandia	Wooden thermometer and hygrometer	$115.99	Two dials	Visit website
Hukka	Soapstone thermometer, droplet	$118	Finnish soapstone	Visit website
Narvi	Black Fahrenheit thermometer	$119	Aluminum with birch frame	Visit website

The Dundalk thermometer at $19 is sold only with a Dundalk sauna at that dealer. The Sauna Place also lists thermometers from $29.99 to $190 for an illuminated Cariitti model.

What normal looks like

Typical readings
Air temperature	Relative humidity on the hygrometer
60°C (140°F)	15 to 30%
80°C (176°F)	8 to 15%

Humidity reads lower as the room gets hotter. Ladling water on the stones raises it for a few minutes. A thermometer on the wall reads air temperature, so it will not match the heater's own set point.

Where to hang it

On the wall opposite the heater, not above it.
At about head height on the upper bench, where you sit.
Away from the door, where cool air comes in.
For a wood stove, a magnetic flue thermometer on the chimney pipe shows when to add wood.

Analog, digital or flue

Analog dial: no batteries and nothing to fail in the heat. Most sauna thermometers are this type.
Digital: keep the electronics outside the hot room unless the maker rates them for sauna use.
Flue thermometer: for wood stoves only. It reads the chimney pipe, not the room.

A thermometer is one of the few accessories every sauna needs. See the full sauna accessories list.

Why readings differ in the same room

Hot air rises, so a thermometer near the ceiling reads higher than one at knee height. That is why the guide is to mount it at the height of the top bench, where your head is. A thermometer by the door also reads low because cool air comes in each time it opens.

How to read a hygrometer

The hygrometer shows relative humidity. In a dry sauna it reads low and climbs for a few minutes after water goes on the stones. If you want a softer, steamier session, ladle more water. If it feels harsh, wait and let the room dry back down. See dry vs wet sauna.

What to look for

Rated for sauna heat: household thermometers are not.
Fahrenheit or Celsius: many Finnish models show Celsius. Narvi sells a Fahrenheit version.
Readable from the bench: a large dial helps in low light.
Wood or stone case: stays cooler to the touch than bare metal.

Which one to buy

Lowest cost: a plain wood dial thermometer and hygrometer, from about $19 to $66 in our check.
Fahrenheit dial: the Narvi Black Fahrenheit at $119.
Wood stove owners: add a flue thermometer ($59) to know when to feed the fire.

Common questions

Where should I put a sauna thermometer?

On the wall opposite the heater at the height of the top bench. Never mount it directly above the heater.

What temperature should a sauna thermometer read?

Traditional saunas typically run about 150 to 195°F. Infrared saunas run lower.

Do I need a hygrometer?

It helps. It shows how much the steam from the stones is changing the humidity.

Why does my thermometer read lower than the heater setting?

The heater senses near its own sensor. The wall thermometer reads the air where you sit, which can differ.