@oylpantr
NO2 layer corresponds to near-surface forecasts based on satellite measurement (see about this data or click the small i in bottom right corner of desktop screen).
So it may be a bit different from air quality stations values measured at ground level.
Windy shows air quality stations, but only few of them provide NO2 values like the one in this screenshot:
7A79FFF9-5269-4AE1-B651-63D7F3644692.jpeg