Mu (μ) / micro (µ) migration breaks InfluxDB and Grafana dashboard

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As described in the 2025.9 release notes breaking changes section, this PR landed that converts uses of the unicode character micro (µ) to mu (μ).

I have my HA instance set up to store long-term air quality sensor data in InfluxDB and visualize it in Grafana. For measuring PM2.5, these sensors use the unit “μg/m³”. This migration breaks all of my existing PM graphs because of the unit “change”:

InfluxDB sensor data in Grafana
InfluxDB sensor data in Grafana2206×678 141 KB

My options to fix this seem to be:

  1. Switch all of the graphs to the “new” unit (μg/m³ → μg/m³). This is tedious and I lose the ability to display the entire history of each sensor (the data now “starts” at the time of the unit change).

  2. Merge the “old” and “new” series (μg/m³ + μg/m³) via a Grafana transformation (“Merge series/tables” transformation filtered to each series pair) for every sensor. This works, but is tedious, error prone, and only applies to the individual graphs in which I specify the transformations.

Are there any other approaches to fix this breakage? Something inside HA itself I can configure to merge these two equivalent units? Something I can do inside InfluxDB? Wondering how others are dealing with this.

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I have merged the data in InfluxDB:
SELECT * INTO "homeassistant"."autogen"."μg/m³" FROM "homeassistant"."autogen"."µg/m³" GROUP BY *

Dropped the old data:
DROP MEASUREMENT "homeassistant"."autogen"."µg/m³"

Exported my dashboards as JSON, searched and replaced micro with greek mu, and re-imported them.

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