25C summer-like warmth on the way for this weekend

The British weather is never one to disappoint when it comes to putting on an exciting show to keep us on our toes.

Last week we shivered in the coldest April spell we’ve seen in quite a while, with temperatures 3-5C below normal and snow falling in southern England – even in London.

This week will see a change in weather fortunes, as warm air gradually drifts northwards, with temperatures well above average for all parts of the UK by the weekend.

As ever, it’s not plain sailing in the sense that it won’t be clear blue sky and sunny for everyone all the time, but it’s definitely going to warm up.

Why is it warming up?

The change to warmer weather is due to the position of the jet stream in the coming days, which will split in two to the west of the UK – known in the meteorological world as bifurcation.

One branch of the jet stream will head towards the Faroe Islands and Scandinavia, with another branch diving southwards across southern Iberia.

The result of this will be for high pressure to build over the Baltic Sea and low pressure to develop over the Bay of Biscay, giving us south easterly winds and a feed of warmer air.

Whilst this means a rise in temperature, there’ll also be an increase in humidity, which means that there’ll also be a risk of some heavy showers – especially towards the west of the UK.

How warm will it get?

England and Wales will see the warmth and the sunshine soonest, with high pressure building from Tuesday onwards, bringing temperatures of 17-21C by Thursday and 19-25C at the weekend.

Scotland and Northern Ireland will have to wait a bit longer for the warmer air to arrive, with cloud, rain and cooler air still around until Friday, with temperatures at 10-15C.

However, at the weekend, the warm air will arrive, widely lifting temperatures to 15-21C by Sunday.

It’s also worth pointing out that even if it doesn’t feel that warm, UV levels will be moderate to high in the sunshine.

UV levels are not dependent on temperature. The sun is strong at this time of year because it is higher in the sky, not because it’s warm.

Will it be sunny all the time?

Sunshine amounts are something worth mentioning, given that newspaper stories sometimes fail to do so when they focus solely on temperatures.

Whilst it is definitely going to warm up, there will be variations in amounts of cloud day by day, with some days bright rather than sunny and others quite cloudy with showers.

The greatest risk of cloudier skies and occasional showers will be across western parts of the UK, with the best of the sunshine towards the east.

However, western areas will have days that are mainly dry and sunny too.

At the moment, it looks like the warmth will last into the beginning of next week – especially across eastern parts of the UK. But, as the week progresses, it’s likely to turn fresher, but not cold.

Don’t forget, you can get the latest forecast on the Channel 4 Weather website. I’ll also be posting regular updates on Twitter – @liamdutton