# helsinki

`https://hel.fi/models/helsinki/helsinki/views/jtjnhkaau64zmzz5csmcwem52icvufy2`

## AirQualityObserved

One air quality station around Helsinki and its newest hourly readings: FMI's stations, and the stations a steward adds by hand, which carry no source.

| Slot | Range | Kind | Required | Multivalued | Description |
|---|---|---|---|---|---|
| location | string | GeoProperty | no | no | Where the entity is, as GeoJSON geometry. |
| name | string | LanguageProperty | no | no | The name, per language. |
| dateObserved | datetime | Property | no | no | When the readings were taken. |
| pm10 | float | Property | no | no | Particulate matter up to 10 µm, the hour's mean at the station. |
| pm25 | float | Property | no | no | Particulate matter up to 2.5 µm, the hour's mean at the station. |
| airQualityIndex | float | Property | no | no | FMI's hourly air quality index, 1 \(good\) to 5 \(very poor\). |
| districtCode | string | Property | no | no | The city's own code of the area: the district number, for a sub-district the full ten-digit code the city's statistics use for it, for a quarter the register's ten-digit quarter code, for a voting district the district number and a letter \(049A\). An HSL fare zone has none; its letter is its \`fareZone\`. The districts, sub-districts, quarters and voting-districts mappings write no area without it. |
| stewardNote | string | Property | no | no | A note by the person who keeps this data: what was checked, what looks wrong, whom to ask. No pipeline writes it and no pipeline overwrites it, so an application may offer it for editing without the next run taking the words back \(AP-62\). At most 500 characters and no angle brackets, because it is a note and not a document. |
| source | uri | Property | no | no | The open-data service the entity was read from. |