Massive bangs woke up residents in Edinburgh forcing the police to put out a message of reassurance as the city was hit with 'Armageddon' thundersnow.
Twitter erupted overnight as the Scottish city was struck by the surprise winter thunderstorm, which peaked with a major 'explosion' at around 4.30am.
Some initially speculated it was trains speeding through in the night but as it got more intense many joked that they feared it was the end of time.
Former Great British Bake Off contestant Tom Hetherington said: "Everyone in Edinburgh being woken up by the thundersnow. Most intense thunder I’ve ~ever~ heard. Literally sounds like bombs going off."
He added that growing up in Chicago he'd heard some "insane" storms as a child "but this was another level".
Another Twitter user said: "Only 2020 could bring us thundersnow."
And another: "Holy s***, being woken up by the sound of insane, exploding #thundersnow over #Edinburgh was borderline terrifying! Good morning to everyone else checking the apocalypse isn’t nigh."
Police Scotland then stepped in to reassure everyone.
"We have received a number of calls regarding people concerned about explosions heard," they wrote.
"Please do not be alarmed, we are currently experiencing thunder and lightning."
Another user then added: "So we're witnessing what is apparently a rare event that can occur in winter under exceptional circumstances.
"Rest assured it is definitely #thundersnow and not the end of the world."
Thundersnow is an unusual kind of thunderstorm with snow falling as the primary precipitation instead of rain.
It typically falls in regions of strong upward motion within the cold sector of an extratropical cyclone.
Lightning produced during winter thunderstorms can strike the ground as well as people and buildings.
In March 1996 thundersnow in the city of Minneapolis, Minnesota, US, reportedly caused a man to be struck by lightning.
Meanwhile, a number of yellow warnings for ice and snow were in place overnight across large areas of Scotland where temperatures were expected to drop to an icy -10C.
The Met Office said the cold spell is expected to last through Friday but that the weekend would see brighter weather and even some sunshine.