Air quality in Slovakia: read the index and the pollutant measurements separately
The Air Quality Slovakia board helps you compare available station observations without opening a separate page for each location. Begin with the station, measurement time, and pollutant coverage. A station’s coloured category is useful context, but it is not a complete measurement of every pollutant on every street nearby.
In this guide
- Air quality in Slovakia: read the index and the pollutant measurements separately
- An index is not a concentration
- A station is not your exact personal exposure
- Hourly observations and health guidelines use different clocks
- Why a fresh page can still show an old reading
- A practical comparison workflow
- Questions readers often ask
The dashboard uses SHMÚ observations and its Index kvality ovzdušia, abbreviated IKO. Do not assume that a numeric index on this board uses the US AQI scale. Different index systems have different breakpoints and category definitions; matching colours or numbers does not make them interchangeable.
An index is not a concentration
A pollutant concentration is a measured quantity with a unit, commonly µg/m³—micrograms per cubic metre. An index combines or maps pollutant information into a rating. An IKO value of 58 and a PM2.5 concentration of 58 µg/m³ would therefore be different statements, even if the numbers happened to match.
PM2.5 and PM10 describe particle-size fractions. Ozone, nitrogen-related measurements, and sulfur dioxide describe different pollutants. Read the pollutant name with the value and unit. A single overall category should not hide which pollutants were actually measured at that station.
| Item on a station record | What to check |
|---|---|
| Station name and location | Whether it represents a traffic, urban, or other monitoring context relevant to your question |
| Observation time | The time of the actual measurement, not merely your page load |
| IKO category and value | The SHMÚ index interpretation, not an assumed foreign scale |
| Pollutant concentration | The pollutant, unit, and averaging period |
| Missing field | Whether that pollutant was unavailable or unmeasured; do not substitute zero |
A station is not your exact personal exposure
Measurements describe air at a monitoring location and time. Traffic near a road, local heating, weather, and the station’s surroundings can produce differences across a town. A nearby station is useful evidence, but it is not a sensor inside your home or at your exact walking route.
Compare similar station types where possible. A roadside reading and a background station may differ for legitimate reasons. Do not turn one high value into a claim about every district, or one favourable category into proof that no pollutant is elevated anywhere in the city.
SHMÚ also distinguishes near-real-time measurements from validated reporting. Treat preliminary observations as useful current information with that quality status attached. A later validated dataset can differ from the first published reading.
Hourly observations and health guidelines use different clocks
An hourly measurement is not automatically comparable with a guideline stated as a 24-hour or annual average. The averaging period is part of the quantity, just as the unit is. A short peak and a long-term average answer different questions.
For example, WHO’s air-quality guidance includes both short-term and long-term concentrations. You cannot establish annual compliance from a single hour, or calculate a 24-hour exposure assessment from one isolated hourly value. Use a complete series and the relevant method when making those comparisons.
For activity or health decisions, follow SHMÚ’s current recommendations and appropriate public-health advice rather than inventing a personal medical threshold from a dashboard colour. The board is a convenient way to inspect observations, not a clinical assessment of an individual’s condition.
Why a fresh page can still show an old reading
Station observation time, source publication time, and dashboard retrieval time are separate. A refresh can successfully retrieve the same old observation. If a station is delayed, its last known reading should remain recognisable as old; it should not be silently interpreted as current clean air.
Missing stations or missing pollutants also change what a summary can establish. An “available stations” total is not proof that every station in the national network reported at that moment. A missing pollutant must not become zero in a comparison or average.
A practical comparison workflow
- Choose the station nearest to the situation you are researching and read its monitoring context.
- Check observation time and any data-quality or freshness indicator.
- Read the IKO category using SHMÚ’s definition.
- Inspect the individual pollutant values with units and averaging periods.
- Compare another relevant station at a comparable time; account for different station settings.
- For health recommendations or official assessment, follow the source guidance and validated reports.
Questions readers often ask
Does a missing PM2.5 value mean the air contains no fine particles?
No. The value may be unavailable or not measured there. Missing is not zero.
Can I compare the number directly with a US AQI website?
Only after establishing that the systems and methods match. This board uses SHMÚ’s IKO source; a different site’s AQI can use different definitions.
Why do two nearby stations disagree?
Their locations, local sources, station types, observation times, or measured pollutants can differ. Compare those details before assuming one sensor is wrong.
Does an hourly peak prove a daily or annual guideline was exceeded?
Not on its own. The relevant average requires observations over the stated period and the prescribed assessment method.
Primary references: SHMÚ’s IKO explanation, SHMÚ’s air-quality FAQ, and WHO’s air-quality guideline explanation.
