Plane contrails have been the source of many conspiracy theories and myths, but they can also help you forecast the weather.

Let’s separate fact from fiction… First, we’ll start off with what plane contrails are.

They’re condensation that forms from high altitude-flying planes. The hot exhaust from the plane meets the cold atmosphere – sometimes as low as 60 below that high up – and creates tiny ice crystals visible over 30 thousand feet below to the ground. This creates condensation trails. For short, we call them “contrails”.

They can be made up of exhaust and dust particles, Just like your car on a really cold day.
When you’re outside and you can see your breath when you exhale, it’s the same principle – the warm air from your lungs meets the cold air.

Using contrails to predict the weather:

When the contrails are long and stick around in the sky for a while, it means conditions are humid and unsettled weather may be on the horizon. If the contrails are short or don’t last long once formed, it means there is less humidity and that air mass is stable.

But contrails haven’t come without their controversy. A recent Harvard study found that with the rapid increase in social media use and other online sites, people have either been misinformed or educated themselves with bogus information.

A growing number of people believe contrails are actually “chemtrails”. Or the release of toxic chemicals into the atmosphere. The supposed goal of these so-called “chemtrails” range from weather modification, to evoke mind control, to spread diseases. It’s usually believed that the government or big businesses are behind it and that they are very good at covering up their tracks.

This theory that planes are spraying chemicals to carry out an agenda is simply not true. Small grains of truth can be exploited to make something seem plausible. The EPA even put out a plan contrails fact sheet to combat some of this misinformation.

A 2016 Cooperative Congressional Election Study of 36-thousand people found that roughly 35% either fully believed or somewhat believed in chemtrails. Those trying to prove this theory have given evidence of increased amounts of barium and aluminum… also, it’s been described as having a taste or smell. There has been no correlation – directly or even indirectly – that plane contrails are carrying out a larger plan

Further literature on “chemtrail” studies:


A 2016 Cooperative Congressional Election Study:


The Guardian:

IOP Science: