You’ll never see a hurricane tear through Britain. Hardly ever experience a blizzard. Or rarely endure a severe drought. What you’ll get is some of the world’s most unpredictable mild weather imaginable. Sunshine and rain on the same afternoon? That’s almost a given. The weather in the UK might be tepid, but it is temperamental and, as researchers have discovered, unique.
So no, you’re not insane for checking the BBC Weather app every hour, or feeling unsure whether to pack a raincoat or sunscreen for work. Because, while we generally follow the four seasons, we’ve all experienced a mini-heatwave in February and freezing rain in July. There has to be a reason why it is the way it is.
Why is the weather so unpredictable in the UK?
Like everywhere else, the UK’s weather is based on our atmosphere—and that can be affected by things like temperature, air pressure, clouds, wind, humidity and rain. The fact that it’s an island and where it’s located, between the Atlantic Ocean and Europe, is what makes it different, as it leaves us exposed to different air masses.
Britain is located directly under an area where five main air masses (and a lesser sixth) meet. These large bodies of air, either polar or tropical in origin, bring various kinds of weather as they battle it out overhead for dominance. They are the main reason why the UK’s weather is constantly changing as they interact.
It’s more common to experience polar air masses (cold, wet weather) in winter and tropical air masses (warm, dry weather) in summer. But, as you’ll know, the odd spell of sunshine in winter, or cold snap in summer, isn’t unheard of. The various air masses can come at any time, and the bigger their differences, the worse the weather can be.
On top, Britain is also in the path of the jet stream. Strong winds, miles above the Earth’s surface, blow from west to east and cause major changes in the air pressure, causing everything from stormy weather to dry skies. Britain’s unpredictable atmosphere has a lot of players, so it’s best to accept that your BBQ may be a washout this weekend.
Why is it also so mild?
Britain can be a confusing place. Constant weather changes, but there’s usually nothing you can’t cope with—until something extreme happens, like a snowstorm, and the whole country shuts down for a week. Overall, it’s often rather mild out, and we have the Gulf Stream to thank for that.
One of the strongest ocean currents in the world, it brings warm water from the Gulf of Mexico into the Atlantic and to the UK. It’s why we have such mild winters here (yes, these are considered mild). Without the Gulf Stream, we’d experience winters closer to Canada, as it’s estimated the British Isles would be 5°C cooler.
There’s been a lot of talk of a Gulf Stream collapse in recent years. The last time this happened was during the Ice Ages over 12,000 years ago. If it happens again, temperatures would plummet, bringing harsher winter conditions to the UK. But, while many predict the Gulf Stream will slow in the 21st Century, an abrupt change is still unlikely.
Is the UK weather getting worse?
Go outside and ask a stranger about that lockdown summer. I bet they’d chew your ear off about the eternal sunshine we had. Because doesn’t it feel like the weather’s become increasingly worse since then? Take off the tin-foil hats for a second, though, because there’s only one big change occurring. Climate change.
Predictably, the UK is getting warmer. The UK’s ten warmest years on record have all happened since 2002. But it’s also getting wetter, with six of the UK’s ten wettest years on record since 1998 (warmer air holds more moisture, creating heavier rainfall). Studies show extreme weather events, like heatwaves and heavy storms, will only become more frequent and intense, but still impossible to predict.