In Slavic mythology, Ognyena Maria (literally "Fiery Mary") is a fire goddess who is the sister and assistant of the thunder god, Perun.
На табе, вада, маю бяду, а мне маё здароўе назад аддай" ("Good evening, dark night!
A strict ban is observed on housework to prevent any disastrous fires on that day, as the summer at July was hot enough to start such outbreaks.
Some Bulgarians believe that as she is the sister of Saint Elijah, she hides from him on St. Elias' Day, to ensure that he would not be so delighted, that his lightning and thunder would destroy everything.
The similar beliefs exist for the Saint Elijahs day, where instead of fires, the disobedient people and their property will be stricken with thunder, ultimately resulting in either decimation of their food supplies and shelter or even in death.
In Ukraine, villagers would pay attention to the lightning in the sky, hoping that on Ognyena Maria's day, this will indicate that God will send rain for their crops.