Hi everyone,

I built this interactive explorer to make it easier to visualize, query, and compare historical air quality and climate data across Europe.

Data Sources:

Air Quality (NO2, PM2.5, PM10, O3): Copernicus Atmosphere Monitoring Service (CAMS) European reanalysis dataset at 0.1° resolution (2013-Present). Climate (Temperature, etc.): Copernicus Climate Change Service (C3S) ERA5 reanalysis dataset at 0.25° resolution. Tools Used:

Frontend: Astro, Tailwind CSS, Leaflet for the map, and Chart.js for the graphs. Backend: Go API with a custom C++ query engine using io_uring to achieve sub-20ms query latency across hundreds of gigabytes of compressed historical data. The tool lets you click anywhere on the map (or search for a city) to see annual averages against the WHO safety guidelines, as well as monthly seasonal trends.

Feel free to check your own city

jiskta.com/explore