What’s the difference between heat lightning and regular lightning?

Question by J-Dawn: What’s the difference between heat lightning and regular lightning?
Or is there really such thing as heat lightning? I grew up in Oklahoma, and there would be sunny cloudless days that got really hot and you’d see flashes of light. We were always told that was heat lightning. There was never any thunder with it. Was it really lightning? If not, what was it? If so, what’s the difference between that and regular lightning?

Best answer:

Answer by Dustin
Heat lightning does not exist. Ask yourself this: What reaction caused by heat alone in the atmopshere causes flashes of light without lightning present? Nothing. There has to be a mechanism to create lightning, such as thunderstorms. Auroras are much slower and are not individual flashes of light, ruling them out as a possibility. Oklahoma is so far south that auroras are extremely rare there as well. Heat lightning is simply this: Very distant lightning in where the bolt is not visible and the sound is not heard. It is the result of a thunderstorm that is blocked from your view by either the horizon or some other object (mountains, more clouds, etc.). The answer below certainly supports this, although I doubt a bolt of lightning would emerge as the result of small dust cloud (thunderstorms are many, many times larger). There may have been other factors at play, but a large enough clouds of airborne particulants can cause lightning as well, such as volcanic ash and dust clouds. In reality, it does not really matter what the factor that caused the lightning was, the fact is, there is always a mechanism at play, weather thunderstorms or particulant clouds, that caused lightning, meaning lightning never resulted from heat alone.

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3 Responses to “What’s the difference between heat lightning and regular lightning?”

  • GC says:

    ‘Regular’ lightning occurs in and around clouds, particularly cumulonimbus. It is caused by the separation of raindrops causing electrical charges on them. When the electrical charges become sufficiently great then a stroke of lightning occurs (very simplified explanation). I once saw a stroke of lightning come from a cloud of dust at an outdoor motorcycle scramble. I can only assume that a similar mechanism is in play in Oklahoma. In hot dry conditions, clouds of dust will become airborne and finely divide dust particles, including coal and flour, very easily become electrically charged resulting in electrical discharges. In a confined space ( a coal mine or a flour mill) this will result in a serious fire. In the atmosphere you will just get a lightning stroke.

  • Peter M says:

    I think I know what you are referring to and it isn’t the scientific answer. The old timers (like me) used to call “heat” lightning the lightning we would see way off in the distance on a hot evening. We would be desperate for rain and were so disappointed by the “oh it’s just heat lightning”. The reason “there was never and thunder with it” was because it was so far away. Of course, if there is lightning there will ALWAYS be thunder, you just couldn’t hear it because of the distance or the way the wind was blowing )away from you).

  • badaspie says:

    Heat lightning is not a scientific term and has nothing to do with how the lightning is produced, or even with the air temperature. It’s simply a popular term for ordinary lightning that is too far away for its thunder to be heard (see links).

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