Why does the sky turn bright green before and during a tornado event?

Sky turns green during tornado event, Sky turns green during tornado event pictures, Sky turns green during tornado event video
Sky turns green during tornado event in Georgia, USA. Picture: Flickr

This apocalyptic green color is indeed a really weird sky phenomenon!

The still unexplained phenomenon indeed continues to mistify scientists… And is local specific! Weird, no?

So why does the sky turn green before a tornado?

Scientists haven’t quite figured out the reason for this phenomenon. Moreover, the greenish-yellow sky before a storm is common in some parts of the world, while totally absent in others.

Here a green sky just before a tornado hit Toronto, Canada:

Their are actually two theories trying to explained this weird sky phenomenon:

1. Air molecules scatter light

To understand this first theory, try picturing mountains in the distance, which often look a deepening blue.

That blue color stems from the scattering of light by air molecules. The same reason, scattered light, causes the sky to look blue.

Now remember that the strongest storms tend to happen late in the day. Some experts think that, before a thunderstorm, golden-reddish light from a sun low in the sky – and a natural bluing effect of the air – combine to create a green sky. The storm provides a dark backdrop and offsets this greenish or yellowish hue

And here an extreme storm video near Big Lake, MN in 2010:

2. Water is intrinsically blue

A different meteorological theory holds that storm clouds themselves may help make the color of the sky bluish-green.

To understand this theory, you first need to know that water is intrinsically blue (sometimes you can see the bluish tint of water in a white bathtub).

It could be that the storm clouds — which are filled with water — provide the color blue, which, again, is illuminated by the golden light of a low sun to create the color green.

Finally a tornado in Brooklyn with green cloud on September 16 2010:

But one thing is sure! If the sky turns green during a thunderstorm, gather up your pets and other loved ones and head for the cellar, a twister my be on the way.

By the way, here another article about the tornado alleys in the US. More tornado news on Wisc.edu, Strange Sounds and Steve Quayle.




  1. It happens over the sea, when waterspouts occur. You can also observe sea water being sucked up into the waterspout.
    Sky turns greenish and orange sometimes.

  2. Seen it myself, twice. Green sky before tornadic activity. The clouds form some crazy shapes too. Hail too. Very surreal experience.

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