# Wildly high PM25 values from api
**URL:** https://community.purpleair.com/t/wildly-high-pm25-values-from-api/22753
**Category:** Data
**Created:** [June 8, 2026, 12:09am UTC](https://community.purpleair.com/t/wildly-high-pm25-values-from-api/22753 "2026-06-08T00:09:51Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Scott\_Beam](https://community.purpleair.com/u/Scott_Beam)
#### Post date: [June 8, 2026, 12:09am UTC](https://community.purpleair.com/t/wildly-high-pm25-values-from-api/22753/1 "2026-06-08T00:09:51Z")
i’ve noticed this for the past several weeks and finally put some logging in to catch it. I’m got dozens of these from just today. pm25 value is over 2000 and sometimes much higher. no way this is correct right? i’ve put some code in on my side to just catch these and set the value i show to at least a more plausible number (300). any ideas?
sensor=206005 sensor\_index=206005 pm2.5=4055.1 dist=18.0km uri=[https://api.purpleair.com/v1/sensors/206005?fields=pm2.5](https://api.purpleair.com/v1/sensors/206005?fields=pm2.5)
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### Author:  [@JMac1004](https://community.purpleair.com/u/JMac1004)
#### Post date: [June 10, 2026, 4:29pm UTC](https://community.purpleair.com/t/wildly-high-pm25-values-from-api/22753/2 "2026-06-10T16:29:47Z")
Possibly dust or spiderweb in the sensor. Blow it out with whatever compressed air you have available.
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### Author:  [@Scott\_Beam](https://community.purpleair.com/u/Scott_Beam)
#### Post date: [June 10, 2026, 6:09pm UTC](https://community.purpleair.com/t/wildly-high-pm25-values-from-api/22753/3 "2026-06-10T18:09:09Z")
i’m a dev using the api, so it’s not my physical sensor. and it’s quite a few with this issue. these are from just the last hour
sensor=126231 sensor\_index=126231 pm2.5=3075.5
sensor=133141 sensor\_index=133141 pm2.5=3329
sensor=123453 sensor\_index=123453 pm2.5=3297.6
sensor=183603 sensor\_index=183603 pm2.5=3328.8
sensor=114745 sensor\_index=114745 pm2.5=3227.3
sensor=48541 sensor\_index=48541 pm2.5=3327
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### Author:  [@Scott\_Beam](https://community.purpleair.com/u/Scott_Beam)
#### Post date: [June 12, 2026, 5:41pm UTC](https://community.purpleair.com/t/wildly-high-pm25-values-from-api/22753/4 "2026-06-12T17:41:33Z")
looks similar to this issue and is just part of having unmaintained sensors out in the world. does make me question the validity of the whole platform though tbh as these sensors age and start pumping out bad data. i’m seeing up to about 100 of these a day in my data
> [@Unusually High Sensor Reading Maintained for Months](https://community.purpleair.com/t/unusually-high-sensor-reading-maintained-for-months/5637/4):
>
> Maybe somebody checked on that sensor and maybe they fixed it? I don’t know what would have caused such a high reading. If it is still reading according to the average going rate for a lot of the stations, then it’s probably good again.
> [@Unusually High Sensor Reading Maintained for Months](https://community.purpleair.com/t/unusually-high-sensor-reading-maintained-for-months/5637/4):
>
> Maybe somebody checked on that sensor and maybe they fixed it? I don’t know what would have caused such a high reading. If it is still reading according to the average going rate for a lot of the stations, then it’s probably good again.
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### Author:  [@Andrew](https://community.purpleair.com/u/Andrew)
#### Post date: [June 25, 2026, 7:42pm UTC](https://community.purpleair.com/t/wildly-high-pm25-values-from-api/22753/5 "2026-06-25T19:42:05Z")
Scott, we have seen this issue occasionally happen with Plantower laser counters before, and we believe it’s an issue with the firmware implementation of CF1 and ATM in the laser counter (firmware we don’t have access to). Try getting the [Alt-CF3.4 data](https://community.purpleair.com/t/what-is-the-difference-between-cf-1-atm-and-alt/6442#p-9928-retrieving-alt-cf34-via-the-api-3) instead.
We’ve got a new map coming soon, and it will display Alt-CF3.4 data by default, with the option to switch back to ATM/CF1 (corresponding with outdoor/indoor sensors).