A chemtrail is a term used by many observers to describe the persistent white trails left behind by aircraft in the sky. While officially classified as condensation trails (contrails) formed when hot jet exhaust meets cold atmospheric air, a growing community of concerned citizens questions whether all trails can be explained this simply. ChemTracker lets you investigate for yourself by showing you exactly which aircraft are leaving trails, at what altitude, and under what atmospheric conditions — so you can draw your own conclusions based on real data.

How does ChemTracker work?

ChemTracker combines real-time ADS-B flight data with atmospheric science to show you every aircraft in your area. It uses your location, live weather data including humidity and temperature at cruising altitude, and the known science of contrail formation to predict which planes are likely producing visible trails. You can point your phone at the sky and see overlaid flight information in real time.

Can I track chemtrails in real-time?

Yes. ChemTracker provides real-time tracking of all aircraft in your vicinity and highlights which ones are currently producing visible trails. Using live ADS-B transponder data and atmospheric readings, the app updates continuously so you can monitor exactly what is happening in the sky above your location at any moment. You can also set up alerts to be notified when trail-producing aircraft enter your area.

What is the difference between a chemtrail and a contrail?

A contrail (condensation trail) is the official explanation for the white lines left by aircraft — formed when water vapor in jet exhaust freezes in cold, humid air at high altitudes. The term chemtrail is used by researchers and observers who believe some trails may contain additional substances beyond normal water vapor, noting that some trails persist and spread for hours while others disappear quickly. ChemTracker helps you study these differences by showing atmospheric conditions, aircraft identity, altitude, and trail persistence predictions for every flight overhead.

Chemtrails Over San Francisco Today

San Francisco, United States · 37.77°N, 122.42°W · Last updated: Sun, 19 Apr 2026 03:02:51 GMT

Current Contrail Conditions

High Likelihood5/8 levels favorable

5 of 8 atmospheric pressure levels currently show conditions favorable for contrail formation.

Solar visibility: Limited · Sun elevation: -3.6°

Atmospheric Conditions by Pressure Level

ChemTracker monitors 8 pressure levels above San Francisco. Contrails form when temperature is below the Schmidt-Appleman threshold and relative humidity with respect to ice (RH-ice) exceeds 70%.

Pressure	Altitude	Temp (°C)	RH-water (%)	RH-ice (%)	Contrail
150 hPa	44,327 ft	-56	3	5	Unlikely
200 hPa	38,637 ft	-61.5	60	106	Likely
225 hPa	36,216 ft	-58	75	129	Likely
250 hPa	34,004 ft	-52.5	76	125	Likely
275 hPa	31,965 ft	-47	76	120	Likely
300 hPa	30,070 ft	-42	76	114	Likely
350 hPa	26,636 ft	-33.4	76	106	Unlikely
400 hPa	23,578 ft	-27.7	75	99	Unlikely

Solar Visibility Over San Francisco

Visibility RatingLimited

Sun Elevation-3.6°

Visibility Factor18%

Solar visibility determines how well contrails can be observed from the ground. Higher sun elevation means better backlit visibility of trail formation above San Francisco.

Frequently Asked Questions

Are there chemtrails over San Francisco today?

ChemTracker monitors real-time atmospheric conditions above San Francisco to predict contrail formation. Currently, 5 of 8 pressure levels show conditions favorable for contrail formation — indicating high likelihood of persistent trails.

What atmospheric conditions cause contrails over San Francisco?

Contrails form above San Francisco when jet exhaust meets air colder than approximately −40°C at cruising altitude (typically 8,000–12,000 metres). Persistence depends on relative humidity with respect to ice — when the air is supersaturated (RH-ice above 100%), trails can last hours and spread into cirrus-like haze. The Schmidt-Appleman criterion predicts these conditions from temperature, pressure, and humidity data.

How does ChemTracker track aircraft over San Francisco?

ChemTracker uses live ADS-B data to track every aircraft over San Francisco in real time. Each aircraft's altitude is cross-referenced against atmospheric data from Open-Meteo at 8 pressure levels. The app shows you which planes are producing trails, their flight numbers, and whether current conditions are favorable for persistent contrail formation above San Francisco.

What is contrail climate forcing near San Francisco?

Aircraft contrails can have a warming effect on the climate, particularly during certain atmospheric conditions. Above busy air corridors like those near San Francisco, persistent contrails and the resulting cirrus clouds can trap outgoing infrared radiation. This effect varies with time of day, season, and local weather patterns. ChemTracker's pressure-level data helps researchers and observers understand when this forcing is most significant.

Nearby Tracked Locations

FremontUnited States San JoseUnited States SacramentoUnited States

All Cities in United StatesView contrail conditions across all tracked cities in United States Chemtrails LiveReal-time trail activity worldwide Contrail ForecastPredicted formation conditions for today and tomorrow Conditions at San Francisco International (SFO)See contrail conditions at the nearest monitored airport

Track Aircraft Over San Francisco in Real Time

See every aircraft above San Francisco with its altitude, flight number, and whether atmospheric conditions at that pressure level are favorable for trail formation.

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