A meteorology professor has identified his primary concern about the polar vortex's impact on the UK — and it is not snow or climate change. Professor Andrew Charlton-Perez, a meteorologist at the University of Reading who researches changes in the Arctic stratosphere, told the BBC that the "concerning thing would be if this event ends up bringing the typical drier weather pattern and lack of rain."
The polar vortex is making headlines worldwide due to "unprecedented" changes in its patterns, raising fears of "weather chaos" including heavy snow, extreme cold, and potential gas supply shortages. Weather experts say "we've never seen anything like this before" regarding the vortex's unusually early weakening this year, known as sudden stratospheric warming (SSW).
Drought conditions persist
With most of England and Wales still in drought after a historically dry and hot summer, the continuation of dry conditions is a concern for the replenishment of reservoirs. The 2026 summer was the hottest on record, with rainfall also at record low levels, though not everywhere in the UK was affected equally. The highest temperature recorded this summer was 38.2C (100.6F) in Gloucestershire on August 13. There were five separate widespread heatwaves, and a temperature of 30C or higher was recorded on 40 separate days.
Prof Charlton-Perez said continued dry weather caused by the polar vortex was more worrying than the prospect of snow. Speaking of the polar vortex and sudden stratospheric warming, he said: "We've never seen anything like this before. Our best records go back to 1979, when satellite observations began, and we have reasonable records back to the 1940s. In all that time, we haven't seen a sudden stratospheric warming earlier than very late November."
Snow unlikely, dry spell a bigger risk
Despite fears of colder, snowier conditions, he said: "An SSW normally means the UK is, on average, colder and drier, with more settled conditions and often blocking high pressure. Because this is so early in the season, I think snow now in the UK is unlikely, and the forecasts don't currently suggest it. There is still too much heat in the oceans, land and atmosphere left over from summer to make snow likely. Later in the winter, the link between an SSW and snowy weather would be stronger."
He added: "Perhaps a bigger concern would be a long dry spell. Our water resources in some parts of the UK are very low after an exceptionally dry and warm summer. Some parts of the UK are still in drought or even severe drought, and we need more than 120% of our usual rainfall every month over the winter to come out of it. If this event or other SSW events during winter bring prolonged periods of dry weather, it could stop our reservoirs from refilling over the winter. That could have extremely significant impacts on water supplies for homes, businesses and farmers next summer."
What is the polar vortex?
The polar vortex is the band of strong winds that develops every autumn as temperatures fall in the Arctic and circles around 18 miles (30km) above the Arctic. Atmospheric changes each year cause the air high up to start warming, known as sudden stratospheric warming (SSW), which then makes the vortex winds weaken. This season, they have weakened unusually early, as most SSW events happen from mid-winter onwards.
In turn, those changes alter the position of the jet stream, increasing the chance of a weather pattern being blocked in place, which can cause drier, colder weather and increase the possibility of snow. Prof Charlton-Perez said: "It's too early to say whether the current record strong El Niño event in the Pacific is the cause of this without more analysis. El Niño usually weakens the vortex and can make an SSW more likely in late winter, during January or February. But the vortex was not unusually weak before this event began. It is still so early in the colder seasons for the northern hemisphere that the vortex hadn't had much time to form or be impacted by the effects of El Niño."
