Air quality is a genuine public health concern across Arizona — particularly in the Phoenix metro area, where dust storms, wildfire smoke, and ozone events can push AQI into hazardous territory with little warning. The Arizona Department of Environmental Quality needed a mobile app that could get actionable air quality information to residents, in their language, on their phone.
What I Built
Air Arizona is a React Native application built with Expo, shipping to both iOS and Android. It pulls real-time air quality readings from ADEQ’s monitoring station network and presents them in a format designed for non-expert users: clear AQI color bands, plain-language health guidance, and location-specific forecasts.
Multi-pollutant tracking covers the six standard EPA criteria pollutants — PM2.5, PM10, ozone, CO, NO2, SO2 — with individual gauges and combined AQI scores. Most consumer air quality apps show only PM2.5; the full pollutant breakdown was a specific requirement for ADEQ’s research and public health programs.
Hourly forecast charts display predicted AQI for the next 24 hours based on meteorological models, letting users plan outdoor activities around air quality windows.
Geofenced alerts use device location to deliver push notifications when air quality at the user’s current location crosses health thresholds — even if that location has changed since the user last opened the app.
Bilingual localization in English and Spanish covers all UI strings, health guidance copy, and push notification text via a structured i18n layer.
The data layer runs through a GraphQL API backed by AWS infrastructure, with a caching layer to handle traffic spikes during air quality events when app usage tends to surge.
Technical Highlights
- React Native + Expo for cross-platform iOS and Android from a single codebase
- Multi-pollutant AQI tracking across all 6 EPA criteria pollutants
- Hourly forecast charts with meteorological model integration
- Geofenced push notification alerts based on current device location
- Full English/Spanish localization via GraphQL API + AWS