Why Do Air Quality Data Differ Between Portals?
The same city may show a different AQI, color, or concentration on different portals. Learn why this is not necessarily an error.
Pages
Explainers on air quality, how it is measured, and how to read the data.
How We Measure Air Quality
AirQuality.city combines its own SensorBox stations with official external stations. Learn what each station type measures and where the limitations are.
How to Read Air Quality Data
A practical guide to interpreting AQI, PM2.5 and PM10 concentrations, measurement time, trends, and station location.
Air Quality Frequently Asked Questions
Answers to common questions about AQI, PM2.5 and PM10, monitoring stations, portal differences, and missing data.
Air Quality in Croatia
An overview of the factors affecting air quality in Croatia, from traffic and heating to weather, fires, and Saharan dust.
Privacy and Cookies
How AirQuality.city processes contact-form and newsletter data and uses essential technical data and services.
Terms of Use
Rules for using AirQuality.city, including limitations of air-quality data, permitted content use, and liability.
About us
AirQuality.city is an independent hobby project created to provide better local insight into air quality across Croatia.
Join us
Help Project Sensorbox, build your own monitoring station, or contribute to the development of AirQuality.city.
Data Sources and Methodology
An explanation of measurement sources, data processing, and PM2.5 and PM10 AQI calculations on AirQuality.city.
What is AQI?
AQI converts pollutant concentrations into a number and category that can be read quickly.
AQI scale
The six AQI categories, their ranges, and a brief explanation of what they mean.
PM2.5 and PM10 particles
What PM2.5 and PM10 mean, where they come from, and why their readings do not always move together.
Other air pollutants
What the NO₂, O₃, SO₂, and CO readings shown by some official monitoring stations mean.
How AirQuality.city processes data
A short overview of data sources, AQI calculation, and the limits of the website's display.