How to calibrate the temperature sensor?

My PurpleAIR measures the temperature to be about 2°C degrees higher than reality. Is it possible to calibrate it?

The temperature sensor in PurpleAir sensors comes pre-calibrated, and our sensors don’t have any process to recalibrate this. However, there are a few potential reasons for the higher temperature you’re seeing.

The temperature sensor used by PurpleAir sensors is located within the device housing. Due to heat generated from the WiFi module, the air inside the sensor is hotter and drier than ambient conditions. This results in raw temperature readings higher than ambient measurements and lower humidity measurements than ambient measurements.

The PurpleAir Map provides corrections that we’ve seen correlate closely with ambient measurements. You’ll first want to ensure that you’re viewing the temperature information using the “Temperature °C” data layer, as this has the correction already applied.

If this is the data layer you’ve been using, your sensor may have an issue related to our 7.04 firmware version. Some users have noted problems with temperature readings on this firmware version. To verify this, you’ll want to check the firmware version for your sensor using the “Firmware Version” data layer (this is currently at the very bottom of the Data Layer list). If it is on 7.04, you can request firmware on your device to be rolled back to 7.02 by emailing Please note that if we roll back your sensor to 7.02, it will remain on this firmware version until you request we update it. Additionally, using 7.02 may result in more inaccurate experimental VOC readings.