United Kingdom: Weather Overview
About United Kingdom
What's The Climate Like In The UK?
The UK is comprised of England, Scotland, Wales and Northern Ireland. It receives a temperate maritime climate with all four seasons but no extremes of temperature. While those dwelling in the UK probably wouldn't agree, the UK's climate could be summed up in one simple word: mild.
As it is a relatively small land mass, there isn't a great deal of regional variation. However, there are a number of microclimates; rain and temperature variations are caused mainly by elevation, proximity to the Atlantic Ocean, and to a lesser extent, latitude. It is generally warmer in the south than the north.
As a whole, the UK is infamous for its changeable weather, cloudy skies and persistent rainfall. The North Atlantic and the Gulf Stream, which meets the west coast, is to thank for milder temperatures than expected at this latitude, but also to blame for the rain and erratic nature of the weather. The east shares a coast with the North Sea, which is considerably colder than the Atlantic as it meets the cold land mass of Europe and is not warmed by the Gulf Stream.
Weather In The UK Major Cities
Rainfall across the UK is not actually particularly high in volume if compared to subtropical and tropical locations, but it does tend to rain frequently all year round. Due to the westerly direction of winds coming in from the Atlantic, areas on the west coast are wetter than those on the east coast. You can see this quite clearly by comparing the precipitation in Cardiff, which lies to the west in Wales, with London - the capital of England in the east of the UK.
While each city sees persistent rainfall across the year, Cardiff has significantly higher average precipitation than London. The average precipitation across the year in London sits at about 40-60mm per month, while Cardiff sees, on average, 60-100mm.
The difference is particularly pronounced in Scotland as the east coast lies in the rain shadow of the western highlands. The west coast of Scotland sees 265 days of rain across the year, whereas the southeast only sees 170 days of rain.
Unprecedented high rainfall has led to a series of disastrous floods. The autumn of 2000 saw exceptionally high rainfall across England and Wales, lasting for over seven weeks. This was the heaviest rainfall recorded in 270 years and led to flooding which affected 10,000 homes and businesses, and forced 11,000 families to evacuate. In spring 2009, the May-July period was the wettest since records began. Some areas were soaked with a month's worth of rain in 24 hours. Counties across England, Ireland, Wales and Scotland were affected, leading to millions of pounds of damage.
UK's Highest Recorded Temperature
The highest temperate ever recorded in the UK was 38.7°C (101.7F), on Thursday 25 July 2019 in Cambridge. Taken at Cambridge Botanic Garden, the number broke the previous record of 38.5°C (101.3F), registered in Faversham, Kent, in August 2003.
Harsh Weather Across Europe
The concern is that this is just the beginning of the UK's freak weather. Flooding in autumn, heat waves in summer and frostless winters could become commonplace as man-made climate change advances. While major floods would have previously only occurred every 100 years, they may start to happen every 10 to 20 years.
However, the winter of 2009-2010 was exceedingly harsh all across Europe. Heavy snow fell all over the UK and throughout mainland Europe, and winter temperatures lasted into the start of spring. It was the coldest winter in 30 years. Meteorologists believe this was as a result of the El Nino weather phenomenon.
Many visitors to London and the UK as a whole are surprised by the length of the days in the height of summer and surprised by their brevity in the winter. Due to its northerly latitude, summer days are long and winter days are short.
If you head to the very north of Scotland in the height of summer you will find the days play host to 18 hours of sunlight, and even when the sun does set, night doesn't properly set in, leaving a prolonged twilight - similar to the 'midnight sun' effect in northern Norway, Sweden and Finland.
South Versus the North
Swimming in the sea around the UK requires quite some courage, despite the warming effect of the Gulf Stream. It is considerably warmer in the very south than the very north, but even in the south temperatures are more bracing than pleasant. The North Sea is colder than the North Atlantic so it also tends to be warmer in the west than the east.
The average water temperature of the North Atlantic off the coast of Kirkwall in northern Scotland reaches a peak of 13°C in August, bottoming out at 7°C in February. The average water temperature of the North Sea around Newcastle, on England's northeast coast, peaks at 15°C in August and gets down to 6°C in February.
The average water temperature of the British Channel at Brighton on the south coast peaks at 17°C in August, and gets to its coldest of 8°C in February. 17°C is just about warm enough for a very refreshing swim, and thousands of obstinate Brits dive in every summer. If you're not from northern Europe, you might find this absurd.
City of London, England.
Scotland lies in the north of the United Kingdom and makes up the northern third of Great Britain. To the south, Scotland shares a border with England. Its north and western coasts are with the Atlantic Ocean and its eastern coast is with the North Sea. Scotland has 790 islands which belong to four groups: the Inner Hebrides, the Outer Hebrides, Shetland and Orkney.
While temperatures in Scotland are, on average, lower than England, the influence of the Northern Atlantic drift keeps temperatures warmer than other locations lying at similar latitudes. The North Atlantic Drift is the northern off-shoot of the Gulf Stream which is a current that brings warmer waters up from the tropics, keeping winters mild.
Extreme Weather In Scotland
As you move further north, winter conditions get slightly more extreme - as they tend to when you move to points of higher altitude. Scotland's most populated area lies in its central lowlands. In Edinburgh, the winter average maximums sit at about 6°C, while the summer average maximums generally sit at 18°C.
Inverness, in the northern Highlands, sees an average maximum temperature of 17°C in peak summer, and an average maximum of 4°C in the coldest part of winter – January. It is common for daytime temperatures to hover around 0°C in the winter, and summer nights are still very chilly, getting down to an average low of 10°C in both cities.
The west coast of Scotland is warmer and wetter than the east coast, due to its proximity to the Gulf Stream, and the southwest direction of winds from the Atlantic. In the west lie the Western Highlands, which is the wettest place in all of Scotland, seeing 3000mm precipitation on average per year.
The high rainfall combined with the warmer temperatures means that parts of the west can get particularly humid in the summer months. When you move away from the highlands, precipitation decreases dramatically – seeing an average of 800mm annually. In the highlands, much of the annual precipitation is made up of winter snowfall. However, there aren't really any ski resorts in Scotland as the mountains aren't high enough. Snow is much less common in the lowlands. Some winters see no snow at all.
What's The Highest UK Temperature for December?
On 28 December 2019, a temperature of 18.7ºC was recorded in Achfary - the warmest December day recorded in the United Kingdom. The unseasonably warm conditions were created by atmospheric conditions knowns as the Foehn Event.
What Is The Foehn Effect?
The Foehn Effect occurs when warm conditions are created when wet and cold air on one side of a mountain causes warmer drier conditions on the other side. Dry air heats more quickly so as it descends it warms up much faster than on the cold side.
Foehn events often happen in the Highlands, where moist prevailing westerly winds meet high ground along Scotland's west coast.
The previous top December Record was 18.3ºC also in the Scottish highlands recorded at Achnashellach in 1948 - again created by the Foehn Effect.
City of Edinburgh, Scotland.
England is mostly flat with the Pennines to the north, and a couple of hilly districts such as the Lake District and the Peak District being exceptions to this rule. Again, the southwest Atlantic winds mean it is wetter in the west than the east, and more southerly latitudes tend to be warmer. Locations further inland are less affected by the moderating effects of the ocean and enjoy slightly warmer summers and cooler winters than coastal areas.
Newcastle, just south of Scotland in the northeast of England, sees temperatures similar to those found in Glasgow and Edinburgh. The summer average high is 18°C and the winter average high is 6°C. Leicester, right in the middle of the country, sees summer average highs of 20°C and winter average highs of 6°C.
This shows that while Leicester's more southerly latitude and distance from the sea makes its summers hotter, in the winter the southerly latitude is negated by the distance from the sea. Brighton, in the southeast, sees average maximums of 19°C in the summer and 7°C in the winter. While its southerly latitude and location on the coast makes winters warmer, the southerly warmth is somewhat tempered by the moderating sea in the summer.
St Ives, on the southwest coast of England, sees average highs of 18°C in the height of summer and average highs of 8°C throughout winter, and an annual average of 1083mm of rain. Broadstairs, on the southeast coast of England, has average highs of 22°C and 7°C in summer and winter respectively, and an annual average of 416mm of rain. This demonstrates the moderating effect of the southwest Atlantic winds; how the moisture they carry starts falling as soon as they hit land, so lessening as they travel east; and the cooler temperature of the North Sea.
Snow falls most winters, but generally only on a few days and some years only on high land.
St.Ives, Cornwall, England.
Wales sits on the central west coast of Great Britain. Its landscape is mountainous so there is quite a bit of regional variation. Temperature drops with increases in altitude and the southwestern faces of mountains are wetter than northeastern faces. Locations lying to the northeast of mountains are often slightly drier than those on the southwest as they are afforded protection from the southwest Atlantic winds. Again, temperatures rise in more southerly latitudes.
Wales is generally wetter and cloudier than England as it is further west. It rains very regularly and more heavily than further east in the UK, throughout Wales, especially on the coast. It is rare for it not to rain more than half of the days in each month. While many would simply consider this a bit of a pain, it has contributed to Wales' famous green landscape.
Llandudno, on the north coast of Wales, sees average highs of 18°C in the summer and 7°C in the winter. Swansea, on the south coast of Wales, sees average highs of 20°C in the summer and 8°C in the winter. Rainfall is marginally higher in Llandudno as Swansea is afforded some protection from its location in the curve of a bay, while Llandudno sits on a peninsula.
Statistics say that clouds completely cover the sky over Ireland for roughly half the time. Upsetting? Yes. Generally, conditions are much the same as you'll find anywhere in the UK, with the same regional variations of easterly areas being drier and southerly locations warmer. However, it is small, largely flat and with a relatively long coast in comparison to its land surface area, so there is less regional variation.
Belfast, in east-central Northern Ireland, sees average summer highs of 18°C, average winter highs of 6°C, and an annual average of 860mm of precipitation. Derry, or Londonderry, in the north of Northern Ireland and to the west of Belfast, receives average summer highs of 18°C, average winter highs of 7°C, and an annual average of 1264mm of precipitation.
Temperatures see little variation across Northern Ireland, but the east is sufficiently protected from the southwesterly Atlantic winds by land to its west to create a significant difference in rainfall.
Belfast City Hall, Northern Ireland.