Best Sauna Thermometer and Hygrometer (2025)
Updated February 2025 — Backyard Sauna Pro
You can't manage what you can't measure. A sauna thermometer tells you when the room is actually ready, not when the heater's timer says it should be. The difference between 155°F and 185°F is significant, session quality, how much water to pour, and how long to stay all change with temperature.
Most kits don't include a thermometer. It's a small purchase that makes a real difference.
Top Picks
Sauna Thermometer Hygrometer Combo
A wood-framed combo unit with both temperature and humidity readings on one face. Cedar or aspen frame stays cool to touch even at 200°F. Glass tube thermometer reads in both Fahrenheit and Celsius. Reads up to 220°F which covers any sauna running at proper temperature.
- Temperature range: up to 220°F (104°C)
- Humidity range: 0-100% RH
- Wood frame (cedar or aspen depending on variant)
- Wall-mount or bench placement
Basic Sauna Accessories Bundle
A good entry-level option that bundles a thermometer with other sauna accessories at a lower per-piece cost. Works well if you're outfitting a new sauna from scratch and want to get everything in one order.
Check Price on AmazonWhere to Mount It
Mount the thermometer on the wall at upper bench level, roughly 4 to 5 feet off the floor. This gives you an accurate reading of what the air temperature actually is where you're sitting, not the floor temperature (always cooler) or the ceiling temperature (always hotter).
Keep it away from the heater and off the wall directly above it. Heat from the element radiates upward and can inflate readings by 20-30 degrees if the thermometer is in that zone. Side wall, mid-bench height, away from direct heater radiation is the right spot.
Reading Temperature and Humidity Together
Temperature and humidity interact. A sauna at 190°F with 5% humidity feels dry and harsh. The same room at 170°F with 15-20% humidity feels more balanced and easier to breathe. Most people prefer the latter once they've experienced both.
The standard guidance: heat to your target temperature, then pour one or two ladles of water on the rocks to bring humidity up to the 10-20% range. Watch the hygrometer and adjust from there. After a few sessions you'll know exactly what your preference is.
Why Not a Digital Thermometer?
Most digital sensors and LCD displays fail above 150°F. The components aren't rated for sustained sauna temperatures. You might get away with a digital unit for a season, but the display degrades or gives inaccurate readings once the electronics heat-cycle enough times.
Stick to glass-tube analog thermometers with wood frames. They have no electronics, last indefinitely, and are accurate enough for sauna use. The only downside is reading humidity with a traditional hygroscopic hygrometer requires more attention than a digital display, but for $20-$40 it's a trade-off worth making.
FAQ
What temperature should a sauna be?
Traditional sauna runs 150-195°F at bench level. Most people find 170-185°F the sweet spot. Infrared runs cooler at 120-140°F.
Do I need a hygrometer in my sauna?
Not essential, but useful. Knowing your humidity level helps you manage the steam experience. Most sauna enthusiasts run 10-20% before adding water.
Can I use a regular thermometer in a sauna?
No. Standard thermometers fail above 120°F. Use a sauna-rated thermometer built for 200°F+ sustained exposure, wood-framed glass tube models are the standard.