The interesting thing about the AVHRR image below are the many violet spots, which are hot spots caused by balefires.
10 October 2023
30 April 2008
By Zdenek Charvat (CHMI)
This is a folklore tradition in many parts of Europe (parts of Germany, Austria, Czech Republic, Slovenia, Sweden) of lighting fires on the evening of 30 April.
This tradition is probably from Celtic origin (or maybe even older) and is related to the Celtic holiday called Beltane. Similar hot spots could be observed in 2007, when there was less cloudiness over Europe; in 2008 the fires can be seen only in the region of the Czech Republic.