DHT22/AM2302 Temperature and Humidity Sensor Accuracy

Electronics Software Development

Earlier this week I wrote an article about how to use the DHT22/AM2302 temperature and humidity sensor with interrupts on an Arduino.; you can see that article here.

After spending more time with the DHT22/AM2302 sensor, I’ve learned the humidity part of the sensor is not accurate at all. The temperature part of the sensor I used was/is quite accurate; accurate enough for a personal weather station, etc.

There are many posts available that describe the process for calibrating this sensor but, I must warn, it’s a long and laborious task.


I have found the following references to aid if you choose to calibrate. Personally, I’ll purchase a more accurate humidity sensor if I need one for a “real” project.


The DHT22/AM2302 sensors have a fairly accurate temperature read; at least the two I tested are.

As for humidity, neither sensor I tested was accurate at all over 50%. If you are needing a higher degree of humidity accuracy you can try the calibration exercises or purchase a more accurate sensor.

All in all, I still recommend this product for learning and testing scenarios.

Bob Mixon

My primary goal in life is to support my family, be a friend and enjoy each day as it may be my last. For work, I am a Senior Office 365 and SharePoint Solution Architect, Senior Information Architect and Microsoft SharePoint MVP. You can read my entire profile here.

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