Sauna Temperature: What to Set for Each Sauna Type

If you're wondering what temperature should a sauna be, the honest answer is that it depends on the type, and the numbers people quote vary by a lot. A traditional sauna runs far hotter than an infrared cabin, and a steam room sits lower still. I don't own a lab or a thermometer fleet, so this page does something different: it lines up what reputable sources actually say about sauna temperature, shows the room-volume math manufacturers publish for heater sizing, and flags where the sources disagree.

Sauna temperature by type, with sources

Here is the comparison I wish I'd found in one place. Every figure comes from a page I opened. The Celsius and Fahrenheit pairs are as each source printed them, except where I mark a conversion as my arithmetic.

Two things stand out. First, the traditional ranges overlap but don't match, and the top of the range changes depending on whether the author is describing a North American home unit or a Finnish public sauna. Second, nobody agrees on a single infrared sauna temperature, which fits what the makers do: infrared cabins heat you directly with radiant panels, so the air inside doesn't need to get as hot.

The angle of this page, in one line: I'm giving you a table where each row has a named source, plus a heater-sizing worked example, so you can check my numbers instead of trusting a confident round figure.

What temperature should a sauna be if it's traditional?

For a traditional electric or wood-fired sauna, the sources cluster around 80–90 °C. Nootka attributes a recommendation of 80–90 °C (176–194 °F) to the Finnish Sauna Society and says no higher than 100 °C (212 °F). I couldn't open the Society's own page, so treat that attribution as secondhand. Healthline's range of 80–100 °C is in the same neighborhood.

Harvard Health puts the ceiling a little lower, at 185 °F for dry heat. That's about 85 °C (my arithmetic: (185 − 32) × 5/9 = 85). So if you want a single best sauna temperature to start with, something in the low-to-mid 70s °C (roughly 160–170 °F) sits inside every range above, and you can step up from there if you like it hotter.

A few practical points matter more than the exact number:

• Where the thermostat sensor sits changes the reading. Harvia's support page says mechanical heaters use thermostats with limited accuracy, while electronic models with a separate sensor reach up to one degree Celsius.
• Air temperature at the bench is not air temperature at the ceiling. A reading taken high on the wall will run hotter than what you feel sitting down.
• Steam from pouring water on the stones feels hotter than the number on the dial. Wikipedia notes that the hottest Finnish saunas have relatively low humidity, with steam made by water on hot stones.

Infrared sauna temperature, and why it's lower

An infrared sauna temperature is lower because the heat source works differently. Cleveland Clinic lists infrared at 110–135 °F and traditional at 150–195 °F in the same article. Healthline gives 45–60 °C for infrared against 80–100 °C for traditional. Wikipedia says far-infrared saunas are generally lower in heat and so more tolerable for people who can't stand traditional temperatures.

On sauna temperature in Celsius, the infrared figures sort out like this across my sources: 43–57 °C, 45–60 °C and 38–65.5 °C. The wide spread in that last one is why I wouldn't pin a purchase decision on a single page. Check the specific model's manual: the maker's stated maximum is the number that applies to the unit you'd actually own, and I couldn't verify any brand's figure for this guide.

Cleveland Clinic's article suggests starting at 110 °F for 5–10 minutes and keeping sessions under 30 minutes. Healthline cites an older review recommending 5–10 minute sessions for vulnerable groups and 10–15 for healthy adults. Those two don't match, which is a good reason to treat any time guidance as a starting point and ask a doctor.

Steam rooms are a different game

A steam room tops out far lower because the air is near 100% humid. Hunker puts the sweet spot at 110–114 °F and says never to exceed 20 minutes at a time. It also warns that an overly hot steam room can be unpleasant and risk fainting or contact with boiling water. That article is a consumer piece that cites other sources, so I'd rate it a notch below a manufacturer manual. Two manufacturer pages for steam generators failed to load for me, so I have no maker-stated steam temperature to give you.

How heater size and room volume connect to temperature

The temperature you can reach depends on whether the heater matches the room. Harvia is a major heater manufacturer, and its support page gives a clear rule: an average of 1 kW of power for each cubic meter of sauna volume.

Cold surfaces change the math. Harvia says one square meter of stone, glass or similar non-insulated surface raises the power requirement as much as adding 1.2 m³ to the room volume, and non-insulated log walls count at 1.5 m³ per square meter. Harvia's US sizing sheet uses cubic feet instead: for each square foot of cold surface (glass, tile walls, brick, concrete, stone, door excluded) add 2 cubic feet to the room volume.

Here's a worked example, my arithmetic, so you can redo it with your own room:

1. Room of 2.0 m × 1.8 m × 2.1 m = 7.56 m³.
2. One 1 m² glass panel adds 1.2 m³ (per), giving 7.56 + 1.2 = 8.76 m³.
3. At 1 kW per m³, you'd need about 8.76 kW as a baseline.
4. Harvia also says the calculator result is in most cases the minimum power required, and it suggests choosing a heater whose min–max volume range puts your number near the middle, such as an 8.5 m³ room with a 6.8 kW heater rated for 6–10 m³.

The takeaway: a heater that is too small will struggle to reach the temperature you want, and cold glass makes it worse. A retailer's chart on Haven of Heat lists examples such as 70–100 cu ft for 3.0–4.5 kW and 175–300 cu ft for 6.0–8.0 kW, and says that when in doubt it is better to size slightly larger. That's a retailer, not a manufacturer, so use it as a sanity check and not as the authority. It also adds 1.5 cubic feet per square foot of glass, which differs from Harvia's 2 cubic feet, so I'd follow the manufacturer for the heater you actually buy.

Infrared cabins skip all this: the panels are built into the cabin, so you don't size a heater to the room. What you control is the thermostat setting, within the maker's stated limits.

What to set by sauna type

If I were setting up a sauna from scratch, here's the rule I'd use:

• Traditional sauna, first sessions: start low, in the 70s °C (roughly 160–170 °F), which falls inside the overlap of Harvard, Cleveland Clinic and Nootka.
• Traditional, experienced user: work toward 80–90 °C only if you're comfortable and your doctor is fine with it. Treat 100 °C (212 °F) as a line you don't cross, since several sources use it as the ceiling.
• Infrared: begin near the low end of the maker's range. Cleveland Clinic's starting suggestion is 110 °F.
• Steam: stay near 110–114 °F.

These are the ranges sources print, not prescriptions for your body. I'm not a doctor and I don't have hands-on data to add.

Safety limits from reputable sources

Harvard Health says people with uncontrolled high blood pressure or heart disease should check with their doctors before taking a sauna. Its precautions include avoiding alcohol and medications that may impair sweating and cause overheating, staying in no more than 15–20 minutes, cooling down gradually, and not using a sauna when ill.

Healthline lists several conditions where you should get medical clearance first for infrared use, among them unstable coronary artery disease, low blood pressure, pregnancy, kidney disease and taking blood-pressure-lowering medications. Cleveland Clinic names pregnancy, active illness and multiple sclerosis (heat intolerance) as reasons to check with a provider. Wikipedia mentions that alcohol or dehydration with sauna bathing raises the risk of sudden death, and that a pregnant woman's core temperature must not exceed 39.0 °C.

Research on sauna health benefits is mixed and in places preliminary. Cleveland Clinic's expert says the research on sweating to detoxify "is still in its infancy". I won't claim benefits here. If you have a heart condition, blood pressure issues or you're pregnant, talk to your doctor before you pick a temperature.

Frequently asked questions

What temperature should a sauna be?

For traditional saunas, sources land between roughly 65 °C and 100 °C depending on who is writing, with 80–90 °C a common target. Infrared runs lower, around 43–60 °C across the sources I read.

What is the best sauna temperature for beginners?

I can't give medical guidance, but the overlap of the sources suggests starting well below the maximum. Harvard says no more than 15–20 minutes in a sauna, and Cleveland Clinic suggests 5–10 minutes at 110 °F for infrared.

What is sauna temperature in Celsius for a traditional sauna?

Wikipedia gives 75–100 °C, sometimes above 110 °C. Healthline gives 80–100 °C. Harvard's 185 °F ceiling works out to about 85 °C (my arithmetic).

Is 100 °C too hot for a sauna?

Several sources treat 100 °C (212 °F) as the top of the range, and Nootka flags burn risk above it. Many people sit well below that. Whether it's right for you is a question for your doctor.

Does a bigger heater make the sauna hotter?

Not by itself. Harvia ties the heater to room volume, 1 kW per cubic meter on average, plus extra for cold surfaces. An oversized heater can create other problems, and Haven of Heat says oversized units create uneven heat and excess electrical draw. That's a retailer claim I couldn't confirm elsewhere.

What I would do

I'd pick the sauna type first, then set the temperature to the low end of the range for that type and move up slowly. For a traditional unit I'd size the heater using Harvia's published rule (1 kW per m³ plus cold-surface additions) and choose a model whose range puts my room volume in the middle. I'd keep any glass to a minimum, since every square meter adds 1.2 m³ to the load. For an infrared cabin, I'd read the maker's manual for its stated maximum and set the thermostat well under it for the first weeks. Whatever you choose, see your doctor first if you have heart, blood pressure or pregnancy concerns, and keep sessions short.

Heater size and sauna type decide what you can reach, so infrared vs traditional sauna is worth reading next, along with outdoor sauna cost if you are budgeting for a backyard build.