Scotland could be hit by a 'rare' snow storm in October, sparking fears of a White Halloween.
After a pleasant start to the month, temperatures have started to plummet due to an 'unusual' weakening in the polar vortex.
October 24 is the suggested date for a drop below 0C in Scotland, with some parts of the country expecting lows of -1C.
Snow could even fall by Halloween - a 'rare' phenomenon last seen 13 years ago in 2008.
According to meteorologists, high intensity winds and severe cold could last until November as the polar vortex goes into reverse.
A polar vortex is a low pressure area - a wide expanse of swirling cold air - that is parked in polar regions. During winter, the polar vortex at the North Pole expands, sending cold air southward.
This happens fairly regularly with outbreaks of cold temperatures reaching the UK or the US.
Former BBC weatherman and meteorologist for Weathertrending John Hammond said: “These high-altitude winds normally intensify as we head towards winter."
"An unusual weakening of the polar vortex may well have impacts on our weather later through autumn and into early winter.
“'Sudden stratospheric warming' events can sometimes lead the polar vortex to go into reverse, which can have dramatic impacts on winter weather and increase the chances of severe cold," he told The Sun.
“The last time that lowland southern Britain saw significant snowfall as early as October was in 2008 - a measure of how rare it is,"
