Real-time contrail formation conditions across 8 cities in France. Data refreshed every 30 minutes.
Last updated: Mon, 20 Apr 2026 05:56:24 GMT
ChemTracker monitors atmospheric conditions at 8 pressure levels above every city in France. The system uses Open-Meteo weather data combined with the Schmidt-Appleman criterion to predict whether aircraft at each altitude are likely to produce persistent contrails.
Contrail formation depends on temperature, relative humidity, and pressure at cruising altitude. When these conditions align — typically when RH-ice exceeds 100% at temperatures below −40°C — aircraft trails can persist for hours and spread into cirrus-like cloud cover.
Track every aircraft over any city in France. Get notified when trail-producing planes are in your area.
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