What Temperature Should a Sauna Be? The Complete Guide
Too cool and you lose the health benefits. Too hot and you risk your safety. Understanding sauna temperature — and how to manage it — is fundamental to the practice.
Sauna temperature is not a single number. It depends on the type of sauna, the cultural tradition, the humidity level, your experience level, and what you are trying to achieve. Understanding these variables helps you evaluate venues, manage sessions effectively, and explain to the sauna master exactly what you need.
Traditional Finnish Sauna: 80–100°C
The traditional Finnish sauna operates at 80°C to 100°C (176°F to 212°F) with relative humidity of approximately 10–20%. This is the temperature range associated with the Finnish studies on cardiovascular health, dementia reduction, and longevity.
At 80°C, the heat is significant but manageable for most healthy adults, particularly on the lower benches. At 95–100°C, the air near the ceiling is extremely hot — experienced users sit at this height, but newcomers should start lower.
The perceived heat also depends heavily on humidity. Adding water to the stones (löyly) increases humidity temporarily to 30–40%, which dramatically increases the felt intensity of the heat. A well-managed löyly at 85°C can feel more intense than a dry environment at 95°C.
Below 70°C: Not a genuine Finnish sauna experience. You will sweat, but the cardiovascular stimulus and heat shock protein activation associated with the health benefits are not fully achieved.
Above 110°C: Rare and not recommended for most users. Some traditional Finnish smoke saunas reach 110–120°C during heating, but are allowed to cool to 90–100°C before use.
German/Aufguss Sauna: 85–95°C
German saunas typically target 85–95°C — slightly lower than the hottest Finnish saunas — to allow for the elaborate Aufguss ceremony, during which the sauna master waves a towel to circulate steam. The circulation of air increases the perceived intensity significantly, making a 90°C Aufguss sauna feel considerably hotter than 90°C still air.
Steam Room: 40–50°C
The steam room operates at much lower temperatures — 40°C to 50°C (104°F to 122°F) — but at 100% relative humidity. Because sweat cannot evaporate in saturated air, the body cannot cool itself efficiently, and the felt temperature is significantly higher than the air temperature suggests.
Steam rooms are gentler for cardiovascular beginners but harder on those with respiratory sensitivity. They should not be mistaken for saunas — the physiological mechanisms are different.
Infrared Sauna: 45–65°C
Infrared saunas operate at much lower air temperatures — typically — because they heat the body directly via infrared radiation rather than heating the surrounding air. The physiological effect differs from traditional sauna: core temperature still rises, and sweating is significant, but the cardiovascular stimulus is milder.
