Purple air temperature jumped 15 degrees F

My sensor is reading 40 to 50° hotter than others in the area power cycled the sensor made no difference check the temperature with a thermal gun surrounding temperature is 40° cooler than with the sensor is reading

I have one unit that’s about 8 degrees F higher than my others since March 16. I have given up on them fixing the problem. I now use other means to check temperature and humidity. I’m using the Purpleair units only for air quality. What a disappointment!

I used to recommend Purpleair, but no longer.

William, this issue was fixed in that sensors were reading about 8 degrees higher after implementing a new driver for the BME68X VOC sensors. This was fixed in firmware version 7.04 though. Can you share some more details about your specific situation? Like which sensor(s)?

Richard, we’d like to know more about this. We’ve looked at your sensor, and the BME280 and BME680 in your sensor are in agreement about the temperature. Therefore, we’re not certain where this issue is coming from, and we’d like to explore further. Can you use your thermal gun to check the temperature of the sensor itself?

We’re happy to do whatever it takes to help you get this issue resolved.

The sensor with firmware 7.04 reads about 5 degrees F higher than my older sensor. I used to remark at how repeatable these devices are. Compare two or more to each other in the same environment, and they were spot-on. My newer indoor sensor was fine. It agreed with the others until March 16. It has never agreed since. I have, as a workaround, implemented other devices to monitor temperature. How can I return the newer, unreliable device?

OP here, my PurpleAir still shows between 5-10 deg F higher than what the two nearby sensors show, and what an independent digital sensor says mounted in the same location. I can’t tell what firmware I’m at, but I would think by now it would have updated, so this is still an issue for me.

Andrew, the temp inside the ranges between 55 and 59 depending where I checked at the wall of the house was 53 and on purple air it said it was 89


Andrew, just a quick thought. Could it be the two LEDs that are on inside the sensor that could be causing the heat?


Richard, this is an interesting idea. Can you send us a picture of this sensor? Send it to contact@purpleair.com. If you’re interested, we’d like to send an identical sensor to collocate with this sensor, just to see what it does. After the experiment is complete, you would be able to keep the additional sensor or give it to a friend.

William, we’re happy to replace your sensor. Please send us an email (contact@purpleair.com).

Garth, your sensor is on the latest firmware. It seems that the fix we made in version 7.04 has not resolved this issue for all sensors. Rest assured, this is a firmware-related issue that we are working to resolve as quickly as possible.


Could you please check also my situation presented earlier?

This issue is not only for temp sensor , same situation occurs for humidity too

Right now the outside humidity is 88% but my purple air says 52% which is wrong
Temp right now is 10.7 purple air says 16 which again is wrong.

I have the latest version installed 7.04


Andrew, I was curious and did another test I took my FireBoard BBQ temperature probes and hooked up 2 probes one on the wall and one inside the sensor I have attached a copy of the trend. Both probes read pretty close to each other the whole time, they were within a few degrees of the ambient temperature. The big spike on the trend is when I use my grill It has its own temperature probe that automatically got added to the trend.


Can you send us an email to contact@purpleair.com with the device ID of the PurpleAir sensor? We’ll be happy to take a look!

Thanks for providing this information!

Sure, I’ve sent all details that you need.

Andrew, the new sensor is up and running it is mounted next to the other sensor


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What’s the status of this bug? Its been 2.5 months since I started this thread, and 21 days since I was told the first fix didn’t work and the second fix was on the way, and my sensor is still showing the wrong temperature. If this is a firmware problem, can you tell me how to install the previous firmware version that worked?

Hi Garth, some of our users are still reporting issues with the temperature. If you’d like to have your sensor rolled back to firmware version 7.02, we can do that for you. Just send us an email with the device ID of the sensor and we’ll get it rolled back for you.

Note that this will likely result in the VOC readings not working properly as they were before version 7.03.

I’ve got a relatively new sensor and it’s also showing strange temp and humidity readings relative to my own weather station (5 feet away) and that of others in the area (weather underground). I notice that many of the purple air sensors in my immediate area are also off by 10-15 degree F relative to the weather stations that are close to them. They’re also wrong about humidity (showing lower than others) and slightly off on pressure).

I would posit that’s a decent sanity check for your team Andrew et al. See where you have decent overlap from a weather/map service for purple air sensors and see how the variation plays out when you push your next update. You’ve got openweathermap.org and wunderground.com to look at and the overlap between weather nerds and air quality nerds is probably pretty high from a correlation standpoint.

BTW - I’m on 7.04, and 2 stations by me (within 1 block in either direction) that also look like they have erroneous temperature data are on 7.02. I’m showing 9-10 degrees high relative to my weather station. one neighbor (on 7.02) is 12 degrees high and the other (also on 7.02) is showing 11 degrees high. The first neighbor has their own weather station on wunderground near their purplair sensor, and for the second I’m lookin at a wundergound sensor 3 houses away from the purpleair house.