I found a discrepancy (a bug?) in Windy in temporal resolution for some station data:
Windy shows hourly resolution (problem)
while PM10 & PM2.5 data are published without hourly resolution , daily only @ Midnight

--> Air quality index seems good, but it's poor!

Here details:

• official station Milano Pascal Città Studi:
  https://www.arpalombardia.it/temi-ambientali/aria/stazioni-fisse/dettaglio-stazioni-fisse/?zona=1&citta=451&stazione=705
  data are published but without hourly resolution for PM10 & PM2.5 , daily only @ Midnight -
  hourly data for NOx, SO2, O3, Benzene
  

while on Windy

• image 1 now Air quality in green, seems good ?!
  

• image 2 at Midnight (PM10 spikes!)
  

see other images

• Windy other stations
  

• same official data, republished throughout Europe, from https://www.eea.europa.eu/en/analysis/maps-and-charts/up-to-date-air-quality-data
  

• other data from https://aqicn.org/station/@156526/it/
  

data source https://maps.sensor.community/#11/45.5335/9.2443