The PM Threshold Exceedances KPI is an exceedance indicator that shows how many times in a month the daily average value of PM10 and PM2.5 exceeded the recommended daily thresholds from international guidelines. It does not provide the absolute concentration of particulate matter, but counts the critical days — those on which air quality was insufficient according to public health and ecosystem protection standards.
This KPI is closely linked to the Air Quality KPI: the reference thresholds displayed in the exceedance chart correspond to the limit values set in that KPI. Important: to generate PM Threshold data, the air quality data must first be calculated and made available.
Data come from Open-Meteo Air Quality (WRD_OPNAQ_99), which provides daily estimates of PM10 and PM2.5 at 11 km spatial resolution, available from 2013 to the present, derived from air quality forecast models (CAMS, Copernicus).
The calculation process involves the following steps:
Unit: number of days per month (days/month)
Note: the thresholds displayed in the chart come from the "Air Quality" KPI configuration and may vary depending on site settings.
| Code | Name | Provider | Resolution | Availability |
|---|---|---|---|---|
WRD_OPNAQ_99 | Open-Meteo Air Quality | Open-Meteo / CAMS | 11 km | 2013 — present |
This KPI is a visualisation indicator and does not have an A–E level range like other KPIs. Its purpose is to provide a temporal representation of the frequency of exceedance events, complementary to the absolute concentration value provided by the "Air Quality" KPI.
| Characteristic | Value |
|---|---|
| Type | Exceedance count (visualisation) |
| Unit | days/month |
| A–E Levels | Not applicable |
| Range | Not configured |
| Prerequisite | "Air Quality" KPI calculation required |
Open-Meteo Air Quality data (WRD_OPNAQ_99, 11 km, 2013–present). Acquisition of daily mean values of PM10 and PM2.5. Comparison with recommended daily thresholds: PM10 = 45 μg/m³, PM2.5 = 15 μg/m³ (WHO Air Quality Guidelines 2021). Monthly count of days where the PM value exceeds the respective threshold. Result: number of days/month with exceedance. Visualisation as monthly bar chart. Prerequisite: air quality data must be generated first.