Air Quality Index, Pollen & Stations
A real-time public health layer for the globe — live AQI heatmaps from OpenAQ's 30,000+ monitoring stations, four pollutant layers, pollen index, and WHO threshold alerts.
30,000+
Monitoring stations
100+
Countries
AQI
Heatmap layer
4
Pollutant layers
Pollen
Index overlay
WHO
Threshold alerts
EPA
AQI standard
Real-time
Station updates
Data Pipeline
From OpenAQ station measurements to AQI heatmap globe in six steps.
OpenAQ Data Ingestion
Real-time air quality measurements are ingested from OpenAQ's 30,000+ monitoring stations across 100+ countries. The OpenAQ v3 API provides station metadata, sensor locations, and the latest measurements for PM2.5, PM10, NO2, O3, CO, and SO2 pollutants.
AQI Calculation (US EPA Formula)
Raw pollutant concentrations (µg/m³) are converted to AQI using the US EPA NowCast algorithm. Breakpoint tables for PM2.5, PM10, O3, NO2, CO, and SO2 are applied to compute sub-index values. The overall AQI is the maximum sub-index across all measured pollutants.
PM2.5 / PM10 / NO2 / O3 Layer Split
Four primary pollutant layers are computed independently as interpolated surface grids using inverse-distance weighting (IDW) from station measurements. Each layer is normalized to its WHO guideline value for comparability across pollutants.
Pollen Index Overlay
Pollen concentration data from SILAM/CAMS pollen forecast model output is processed for tree, grass, and weed pollen types by season. Daily pollen index values are mapped to a 0–5 scale (Low to Very High) for overlay on the globe.
WHO Threshold Alerting
Stations where AQI or individual pollutant concentrations exceed WHO Air Quality Guidelines (2021 revision) are flagged for visual alerting on the globe. Exceedance severity is classified into WHO bands (Good / Moderate / Unhealthy for Sensitive / Unhealthy / Very Unhealthy / Hazardous).
Globe Rendering
Station dots, AQI heatmap tiles, individual pollutant layers, and pollen index overlay are composited on a globe.gl WebGL globe. Layer switching, AQI color scale legend, and click-through for station trend charts are all handled in real time.
Tech Stack
OpenAQ v3 API
AQ data
globe.gl + Three.js
Globe renderer
WebGL
GPU rendering
US EPA NowCast
AQI formula
WHO AQI 2021
AQI standard
SILAM / CAMS
Pollen model
IDW spatial grid
Interpolation
Next.js App Router
Framework
🌿 Key Capabilities
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Live AQI data from 30,000+ OpenAQ monitoring stations across 100+ countries
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PM2.5, PM10, NO2, and O3 layer toggles with independent IDW-interpolated surface grids
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Pollen index overlay by season and region from SILAM/CAMS forecast model
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WHO threshold alert visualization with 6-band severity classification
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City-level trend charts on station click with historical comparison
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Historical comparison by date range for seasonal and trend analysis
Monitor air quality across the globe in real time
Live AQI heatmaps, 4 pollutant layers, and pollen index on a single 3D globe — built for public health, environmental, and urban planning teams.
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