About AirQuality.city
AirQuality.city did not begin as a business plan or an institutional programme. It started in late 2021 with a much simpler idea: measure what was happening in the air at a location where official monitoring did not provide enough local detail.
The first SensorBox combined a Raspberry Pi, a particulate-matter sensor and a small amount of code that turned raw readings into data on a screen. That practical experiment gradually became a portal that now brings together its own measurements and publicly available data from official monitoring stations across Croatia.
Local data matters only when its context is clear
Air quality can change markedly over a short distance. A busy road, a row of domestic chimneys, an industrial source, a valley, a change in wind or a short episode of smoke can produce conditions that look very different from those recorded several kilometres away.
AirQuality.city therefore does not treat a single number as an answer for an entire city. The portal shows the station location, measurement time and trend, together with additional pollutants and meteorological data where they are available. The aim is to provide context, not merely a colour on a map.
SensorBox fills gaps between official monitoring sites
AirQuality.city's own SensorBox stations primarily measure PM2.5 and PM10. They use low-cost optical sensors that are useful for detecting local changes and recurring patterns, but they are not regulatory instruments and are not presented as such.
The value of this kind of network lies in density and continuity. An official station must meet demanding technical and regulatory requirements, while a small sensor can help fill the space between official sites and reveal when something unusual is happening in a neighbourhood that deserves a closer look.
Official data remains the basis for official conclusions
AirQuality.city also displays publicly available data from Croatia's official monitoring networks. Real-time or near-real-time values may still be preliminary until they have passed the provider's validation process, so the portal distinguishes between an informative current view and final regulatory data.
Health, legal, regulatory and other official decisions should rely on competent authorities and validated sources. AirQuality.city is designed as an overview, an explanatory layer and an additional source of local detail, not as a substitute for the official system.
The project remains independent
AirQuality.city is an independent, non-commercial hobby project developed in spare time. Hosting, hardware, maintenance and new stations are funded mainly privately, with occasional help from people who contribute equipment, locations, expertise or time.
The core team is small, but the project has never been built in complete isolation. Advice, testing, donated or loaned hardware, Raspberry Pi computers, sensor locations and ideas from other people have all shaped what the portal has become.
Measurement is the beginning of the story
The most interesting part of air quality is rarely the number itself. The more useful questions concern what happened before a value rose, how long the increase lasted, whether nearby stations recorded the same pattern, and whether traffic, heating, weather, a fire or pollution transported from farther away can explain it.
AirQuality.city is therefore developing in two directions at once: better measurements and better explanations. Alongside maps, charts and station pages, the site is building a body of editorial content that places those measurements in context. Data becomes more useful when it can be understood, compared and checked.