Why does my thermostat humidity reading not match my hygrometer?
Thermostats and standalone hygrometers often display conflicting humidity levels because of placement differences or sensor calibration errors. This discrepancy creates confusion over which reading to trust and raises concerns about hidden mold growth if high levels are real.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1bringing in a third instrument to find an averageDid this help you?
- 2ignoring the standalone device and trusting the thermostatDid this help you?
- 3adjusting for temperature differences and heat generated by the thermostat displayDid this help you?
- 4building a wet bulb thermometer and consulting a psychrometric chartDid this help you?
- 5turn the dehumidify settings off on the thermostatDid this help you?
- 6warranty the unitDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Feels fine but I am concerned about hidden mold growth if humidity is consistently over 60%.”source ↗
“I am dealing with the exact same situation. I think the key is having two or three standalones for better accuracy. I have only one myself, but need to pick up two more.”source ↗
“The thermostat is reading almost 20% higher than every other sensor in the house.”source ↗
“With the humidity reading being so far off I had to turn the dehumidify settings off on the thermostat because it was never getting the humidity down according the to thermostat even though it was actually lower in the house.”source ↗
“Our humidity reading on the thermostat is extremely high compared to a standalone hygrometer. Which is more reliable/how can I recalibrate or adjust the thermostat if needed?”source ↗
Where this came up
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