Last night heat lightnings were observed all around Southern Finland! The lightnings were caused by a thunderstorm cells that were moving northwards from the Gulf of Finland to mainland. The lightning activity was pretty intensive, and I could observe several lightnings in a minute! I didn’t hear sound of thunder ever during the night, which means that the lightnings were pretty far away!
Heat lightning means a silent lightning flash, which is observed without the sound of thunder. Heat lightnings doesn’t have anything to do with heat, and term heat lightning is used because these lightnings are often observed when surface temperatures are warm. According to Accuweather, the name of the phenomena originates from an old wive’s tale, that a hot weather can generate lightnings without a thunderstorm, but this of course, is just a myth, as Accuweather explains.