What is St. Elmo's Fire?

Mary McMahon
Mary McMahon
Woman with hand on her hip
Woman with hand on her hip

St. Elmo's Fire is a weather phenomenon that has attracted attention and comment for hundreds of years. This phenomenon manifests in electrical storms and other weather conditions that generate atmospheric electric fields. When conditions are right, a glowing blue to green light can appear around things like lightning rods, pipes, and the masts of ship. While St. Elmo's Fire looks like a fire, it is in fact plasma, gas that has been ionized due to the presence of an extremely large electrical field. Once the charge dissipates, after a few seconds or minutes, the light vanishes along with it.

Many people have actually seen St. Elmo's Fire, but they might not have realized it. Neon lights are a carefully contained and controlled form caused by turning gases into plasma. Neon lights come in a range of colors, depending on the gases enclosed in the tubes; the mixture of gases in the Earth's atmosphere is what causes the natural phenomenon to appear green to blue in color.

This interesting weather event is named for the patron saint of sailors, Saint Erasmas of Formiae, also known as St. Elmo. Sailors often witnessed St. Elmo's fire on their journeys, and superstitions came to be attached to the mysterious glowing plasma; many sailors felt that its presence was a sign that the saint was looking after them. St. Elmo's Fire can also appear on land, tending to concentrate around pointed objects which concentrate electrical charges.

For the phenomenon to manifest, a grounded object must discharge electricity in a charged atmospheric field. The electricity from the grounded object ionizes the surrounding air, pulling the molecules in the air apart and creating what is known as a corona discharge, a prolonged electrical spark which causes a momentary bright flash. Storms are ideal for creating St. Elmo's Fire because they tend to generate charge differences, creating the circumstances necessary for the corona discharge.

If a person is close enough to St. Elmo's Fire, he or she can hear it buzz or hiss sometimes. Because the corona discharge is simply glowing plasma, rather than an actual fire, it will not cause objects around it to catch fire, and sometimes the light can be coaxed into doing tricks. Airline pilots, for example, have written about playing with it when it gathers outside their windows, trailing their fingers across the windshield to attract the plasma.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


I've always wanted to see the Northern Lights, and now I'd like to see St. Elmo's Fire, also.

My grandfather left home when he was 16 to be a sailor in the North Sea. He never mentioned it, but he must have seen St. Elmo's Fire a number of times. Can you imagine what a thrill (or a scare) it would have been for a teenager to see such a sight out in the middle of the ocean? It's interesting that this phenomena was named after St. Elmo, the patron saint of sailors.

I remember seeing the movie St. Elmo's Fire in the 1980s and I still listen to the soundtrack. The songs make references to the electrical event.

I think that there are a lot of people who don't have any idea what St. Elmo's Fire is, especially kids. It would be a good thing to cover in school.


@ddlJohn - My little boy is a Gemini, and I find this to be an incredibly awesome tidbit to regale him with!

I utterly love discoveries such as this that will draw his interest and get him involved in using that beautiful, as of yet uninhibited imagination.

I had never heard the story of St. Elmo’s fire – or of Pollux and Castor – until now. Likewise, I’ve certainly never witnessed the blue light during a storm.

Now, however, I’ve got a new little ditty to entertain and capture my little one with! Thank you!


Oh, this is so cool. Don’t you just love these sorts of things that have long been held a part of mythology and superstition, and then we discover the answers behind them?

I personally absolutely believe in the paranormal and that many superstitions certainly hold some truth to them.

Now, that does not mean that I think that the two Gemini twins are out there causing St. Elmo’s fire, but that science is slowly explaining paranormal events as we learn more and more about the workings of the universe.

In other words, paranormal – to me – is just a word that gives us a definition to hang on events and things that are as of yet indefinable otherwise. That doesn’t mean, however, that they will not one day be explained in full.


How enlightening! I’ve heard of St. Elmo’s fire, but never actually new what it was. I’ve certainly never laid eyes on it before!

And, now I am absolutely determined to do so. I am terrified of lightning storms and the like, but this just sounds so incredibly interesting.

Where are the best places to find it and are there are any particular weather conditions other than a lightning storm to look for in order to up your odds of catching the phenomenon in action?

I cannot wait to have a chance to check this out! This is probably the first time in my life I’m looking forward to a storm rather than being petrified of it!


@bluespirit - From what I can tell there is no special local, rather as the article described you have to be around things such as lightning rods and masts of ships during a storm.

I was curious about this because I had learned about many saints growing up around the Catholic Church but I had never heard of St. Elmo. But now I realize that because I never had been on ship that was likely my cause of never having learned about him.

Fun fact: I thought St. Elmo must have been a sailor. Actually it is thought that his connection to lightning that made him the patron saint of soldiers and why this phenomenon may have been named after him.


I thought St. Elmo's Fire just had to do with the movie and the brat pack! I had never seen the movie as it was a little out of my time period, but had heard of it and the brat pack when I had seen interviews of Charllie Sheen or Rob Lowe (who were in the movie and in the brat pack).

While they are handsome and good actors, I think this description of St. Elmo's Fire is much more exciting than the movie!

Where are you most likely to see St. Elmo's Fire or is there a most likely place?


@fify-- Yes, I've heard several myths and legends about St. Elmo's Fire as well. Some sailors and fisherman also considered St. Elmo's Fire to be God's helping hand.

I believe the Greeks thought that St. Elmo's Fire were the Roman mythological twins called Pollux and Castor. The twins were known to help sailors and other shipwrecked people on the sea. These twins are also associated with the astrological sign Gemini.

The one thing that all of these legends have in common is that there is some sort of divine, out of this world intervention. But people who are not familiar with the seas don't really know about St. Elmo's Fire unless they witnessed it on land.

There is also an old song and film from the 80s called St. Elmo's Fire. Most people are probably more familiar with those.


@turkay1-- No, St. Elmo's Fire doesn't pose any danger for the people or objects around it. Most people are scared of it because they know it involves electricity, but really the amount of electric discharge is nowhere near enough to cause harm.

What I find even more interesting than the actual St. Elmo's Fire phenomenon are the stories and various interpretations of it among common folk.

They say that since St. Elmo's fire appears as a thunderstorm is dying down, sailors have believed that it is the helping hand of St. Elmos protecting them against the storm.

When I was in Asia, I heard interpretations that were exactly the opposite. The fisherman there believed that St. Elmos Fire was a bad omen and probably the presence of a spirit that wanted to harm them. Some even believed that it was the soul of a person who had been killed and was looking for revenge!

It's amazing how when people don't know the science behind an event, they find the most peculiar explanations for it. I wonder what other stories are out there about St. Elmo's Fire.


This is very interesting! I had never heard of this before.

I understand that St. Elmo's fire has nothing to do with actual fire but can it be dangerous otherwise if someone stands inside the "fire" for a while?

Or does it cause damage to electrical objects?

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