UK set for temperature rollercoaster as chilly nights follow warm days

High pressure lying over the UK means that above average temperatures and spring sunshine will continue for the next few days.

All four UK nations have seen their warmest weather of 2026 so far over the past few days with the peak being 20.9C at Gogerddan, west Wales on Wednesday.

But the clear skies that bring the sunshine and warm conditions also mean that overnight temperatures can drop significantly.

Some locations in the Midlands and southern England experienced a day/night temperature difference of around 21C following Wednesday's warmth which was followed by a sharp frost Thursday morning.

Clear skies and light winds this time of year can mean that the ground warms up quickly by day, in the strengthening spring sunshine pushing temperatures up. However, with a lack of cloud overnight, this also means that heat escapes quickly once the sun sets.

During spring, we still have relatively long nights, and cool surface temperatures, meaning the variation in temperatures over a 24 hours period can be particularly stark.

South Newington in Oxfordshire reached 19C on Wednesday, then plummeted to -2.4C overnight.

Woburn in Bedfordshire reached 19.4C before tumbling to -1.6C.

On Friday, Fyvie Castle in Aberdeenshire reached 20C after a very chilly -2.9C start.

These huge swings are known as the diurnal temperature range. Put simply, it is the difference between the highest and lowest temperature of the day.

Afternoons are normally the warmest part of the day because the sun has had time to warm the ground and surrounding air, whilst the coldest time is usually dawn as the ground has lost heat throughout the night.

Ultimately solar radiation determines these temperature swings.

The strength and amount of direct sunshine available is always changing with sunnier longer days giving a greater warming potential than cloudy dull ones.

The air, land and sea absorb and release heat at different rates, with land being more reactive than the sea. The upshot is the ranges can often be greater away from the sea.

Hillier areas see greater swings in temperature too. Plus humidity is a big factor as moist cloudy air slows both heating and cooling because water vapour absorbs the heat.

Local geography also plays a part with different surfaces storing heat in different ways, and this can impact both the temperature by day and night.

Friday morning dawned on a chilly note again. However, parts of England and Wales, have seen more extensive fog and low cloud that traps warmth, so it hasn't been quite as cold as recent mornings.

Afternoon temperatures aren't expected to be quite as high as Wednesday or Thursday but still above average, peaking at around 13 to 16C.

Into the weekend, high pressure stays in charge for most, but a weak front will approach from the Atlantic bringing slightly cloudier and breezier conditions to the north-west of the UK.

Both the lowest temperatures overnight and highest by day will be found towards southern and eastern England, whilst temperature changes will be more subdued towards the north-west.

Spells of hazy spring sunshine should be fairly widespread over the next few days before we see a gradual transition to something a little cooler and more unsettled into next week.

To get the very latest forecast where you are, check online or via the BBC Weather app.