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RuuviTag Brings a Sauna Thermometer to Your Mobile

A sauna in a winter landscape

We Finns are known for our sauna culture. Saunas can be found everywhere in our Nordic country: city homes, country cottages, hotels, sports centres and gyms — even at the Finnish Parliament. It’s hardly surprising that it’s considered one of our favourite pastimes regardless of age, gender or social status. Heating a traditional sauna is almost like a ritual, a family tradition passed on from generation to generation. In this article I will tell you about saunas and more importantly about the best sauna thermometer there is!

Ruuvi, a Finnish technology company, created an environmental sensor that can be used where others fail due to high temperature and other challenges unique to saunas.

Here is a short video about how to use RuuviTag Pro as a sauna thermometer:

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Sauna Thermometer made by Finns for everyone to enjoy

Isn’t it natural that a company coming Finland can make an environmental sensor that functions as a sauna thermometer?

Wireless sauna thermometer alerts you when the sauna is ready

It’s late Friday at the home office. You’re pushing through your last tasks when your phone suddenly vibrates in your pocket: it’s an alert notification from the Ruuvi Station app telling that the temperature inside your sauna has reached +75°C. It’s time to unwind and relax.

Man looking at his watch
No more looking at the watch: RuuviTag will trigger an alert on your mobile phone when the sauna is ready.

Using RuuviTags is that easy: install RuuviTag into a safe place inside a sauna, add the sensor in the Ruuvi Station app and configure a temperature alert — your brand new wireless sauna thermometer has been installed. Furthermore, it has arrived on your mobile!

Unique environmental challenges for a sauna sensor– temperature and the beacon

Traditional saunas, such as the smoke sauna, can take hours of preparation before use and require special care during the process. The dark black interior of the smoke sauna is created by the soot that burning wood releases inside the room. Soot is not dirt, though — it’s known to have antibacterial properties similar to charcoal. The lingering smoke aroma inside the smoke sauna makes it unmistakably unique.

But soot can spell trouble for a sauna sensor, wholly unprotected from the fine particles created through the burning process. RuuviTag is housed inside a protective case, which covers it from dust and other delicate particulate matter, and prevents the beacon sensor from getting into direct contact with water. The environmental sensor breathes through a special IP67 certified water-resistant vent sticker allowing the sensor to accurately measure the surrounding conditions.

Birch bath broom and a bucket in a sauna
Smoke sauna presents unique challenges for environmental sensors.

Saunas aren’t precisely friendly places for electronic devices: temperatures can typically reach 70–100°C, and temporary humidity, as well as the possibility to get in direct contact with water, are genuine threats for any electronic components.

Using an environmental sensor inside a sauna requires careful planning, and choosing the right one for such challenging conditions can prove difficult. Finnish RuuviTag is an excellent choice due to its temperature range (up to +85°C, when fitted with an extended temperature range battery), as well as the humidity and water resistance provided by its unique enclosure. RuuviTag Pro on the other hand is equipped with an extended temperature range battery and it works up to +85°C right from the box.

Few points to keep in mind when using RuuviTag in a sauna

Even though Ruuvi is a great fit to be used in a sauna as a wireless sauna thermometer, there are still a few things to keep in mind when using electronics in such a hostile environment.

If the temperature of the sauna is greater than the temperature range in the device, you should move the device lower so that the temperature is not so high. Even with lower temperatures you can tweak the temperature alert to notify you once the temperature is ideal for you.

Also, RuuviTag should be attached vertically to, for example, a wall so that water cannot sit on top of the breathing hole for long periods of time.
Like any other thermometer with mass, RuuviTag has a short delay in its measurements as the temperature of the sensor takes some time to change. In practice this doesn’t affect measurements that much but it’s good to keep in mind that almost nothing changes instantly in real life. Here is our article about how the delay works in our products.

Most popular types of Finnish saunas

A traditional sauna consists of a stove used to burn dry wood and a basket of rocks, where water is thrown to increase the humidity inside the room.

A smoke sauna (savusauna) is considered the original Finnish sauna experience, and it’s known to provide a soothing and soft heat with a light smoke aroma.

Another variation of wood-burning sauna, typically called a sauna with chimney (puusauna), uses a chimney on top of the stove to guide the released smoke outside the sauna room. The experience is comparable to the smoke sauna, minus the smoke aroma provided by burned wood.

Inside of an electric sauna
Electric sauna is the popular choice for modern Finns (Image credit to Esa Riutta).

The modern electric sauna, which is a sauna fitted with an electric stove, was initially invented in Finland in 1938, and it’s the popular choice in contemporary Finnish society: it’s easy to use. It can be fitted inside a city apartment with ease. Real sauna enthusiasts might claim that an electric sauna misses the authenticity of a traditional sauna. Still, hundreds of thousands of city-dwellers with their private saunas consider access to the sauna a luxury that the modern Finn profoundly appreciates.

Public and shared saunas provide access to anyone, and it’s also one of the rare places where stereotypically quiet and introverted Finns gather to socialise and relax.

Land of a thousand lakes…and million healthy saunas

European bathhouses and related traditions date back to 7000 BC. Although Finnish bathing habits are poorly documented in history, it’s believed that European bathing culture would have arrived in Finland around the same time. The Earliest written mentions and descriptions of sauna customs in the historical region were written by Nestor the Chronicler in 1112.

The age of Reformation and the arrival of Lutheranism shook Scandinavia around 1530. Although bathhouses were primarily destroyed in Europe during that time, and bathing became largely unpopular, the Scandinavian population continued to bathe.

Finnish sauna by a lake
Finland: land of a thousand lakes…and million saunas.

Historically sauna has been a place that provided health and hygiene, shelter and relief from the cold, where children were born, and where the deceased was washed and prepared for burial. It’s not surprising that sauna has also found its way to Finnish folklore (Kalevala — Ilmarinen’s wedding) and art (Akseli Gallen-Kallela — In the Sauna). Sauna tradition is deeply rooted in the fabric of Finnish society.

In the modern-day, it has been estimated that there are over two million public and private saunas in Finland, for a population of 5.3 million.


Using a particular wireless sauna thermometer can upgrade your sauna to the next level.

RuuviTag is a highly user-friendly environmental sensor that can operate in an extended temperature range, such as typical sauna conditions. Its unique protective enclosure allows using the tag safely in traditional and modern saunas.

Buy RuuviTag and make your sauna-experience more pleasant
Receive notifications when the sauna is warm enough and save energy by optimizing the sauna experience!

Buy RuuviTag and make your sauna-experience more pleasant

Receive notifications when the sauna is warm enough and save energy by optimizing the sauna experience!

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I never used a measurement app before, is it complicated?

Not at all. Our app is straightforward, easy to use and our customer satisfaction rate is very high. We stand for quality!

Is the Ruuvi app free of charge?

Correct, the Ruuvi Station app free, fast to set up and very beginner-friendly.

What is the best wireless sauna thermometer?

The best wireless sauna thermometer is RuuviTag Pro 3in1! It’s durable, accurate, easy-to-use and it’s from the home country of saunas themselves, Finland!

What is the best wifi sauna thermometer?

RuuviTag and Ruuvi Gateway work with wifi technology enabling you to read your sauna’s temperatures at all times via internet. You will also receive a notification once the sauna is warm enough.

Do you need a sauna sensor?

Well, a sauna sensor is not a must but it is really useful. It helps you to save energy as you receive an alert once the sauna is ready to use. Also it helps you to optimize your sauna experience as you can see data from your sauna.

Where to find a proper sauna thermometer?

RuuviTag is a proper wireless sauna thermometer and you can order it online from our website. Many resellers also sell our product. You can find a complete list of our resellers from the top navigation bar on our website.

Click here to go to measurement use cases.

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