An extensive heat dome is dominating the southern half of Europe this month, and it’s nowhere near its end. Upcoming days will bring an intensifying heatwave across western and central Europe, with temperatures pushing close to 40 °C in many areas. Summer heat will also spread into England early next week.
According to the forecasts of the global weather models, temperatures throughout mid-August will remain much above average across Southern, Central, and Western Europe. The most anomalous hot temperatures are expected to continue across France, Benelux, the Iberian peninsula, Italy, and the Balkan peninsula.
The scorching heat is forecast to remain across a large part of the continent for at least another week or two.
August started with significant warmth and heatwaves in the southern half of Europe and extended into parts of France, central Europe, and the Balkan peninsula.
Temperatures are repeatedly pushing into the mid-30s, locally close to the 40 °C threshold. Parts of the Iberian peninsula are even past this mark.
Below is the current heat spread across Europe this Friday, August 9th, 2024. The extreme heat will now spread north again.
Up to +43 °C was reported from part of the central Highlands in Spain on Friday, with hotter temperatures further south across Morocco and Algeria. An astonishing +43.7 °C was recorded at Errcachidia, Morocco, 1100m above sea level.
Daily records are being shattered in northwest Africa under the ongoing heatwave.
This weather pattern will continue to intensify over the weekend and extend into mid-August. At the same time, a gradual spread of scorching weather will follow up after Sunday and spread towards the north over France, the UK, Benelux, and central Europe next week.
The general weather picture indicates that a blocking high – the upper ridge – will strengthen from the western Mediterranean region into France and Benelux, also reaching the UK, thanks to a heat dome dominating the southern and central part of the European continent aloft.
What is a Heat dome, and why does it bring long-lasting heatwaves and excessive temperatures?
The Heat Dome is generally the primary background feature that causes yearly intense heat waves. During the summer of 2023, there were extreme heatwave events, which continued into September and October. There have been thousands of record-breaking stations, and the temperature anomalies have often been off the charts.
Similar events occurred across the Balkan peninsula and Eastern Europe through mid-late July this year.
Heat waves are again breaking records this summer, and their longevity and nighttime lows are especially astonishing. Also, on the global scale, July 21st set the new world record for the daily global surface air temperature. It was 17.09 °C, breaking the old record by 0.01 °C on July 6th, 2023.
Global temperatures from January through July this year have exceeded the long-term averages. This anomaly has been so significant over the last 12 months that the chart provided by CopernicusEU undoubtedly speaks for itself.
The Heat Dome is that feature that leads to these extreme heat events. Usually, the heat dome is the main and the most dominant feature of summer weather patterns in Europe and North America. Still, it can also occur in autumn, as we are experiencing last year.
We hear the term heat dome when extremely high and anomalous temperatures develop. Here is how it works and why it is essential to understand it from a larger scale. The upper-level ridge pattern, or warm air mass in the higher altitudes, is known as the Upper High (we often use the term blocking High). It usually forms the heat dome.
So, this specific term is used when a broad area of high-pressure parks over a large portion of the continent. If the event is exceptionally stable and extreme, it usually stays there for several days or weeks.
The heat dome works like a lid on a pot. The extensive dome of heat traps a significantly warmer air mass at all levels underneath, sinking its layers toward the ground. Therefore, the air mass becomes dry and significantly warms as it reaches the lowest elevations.
A heat wave associated with a heat dome creates fair, stable weather and an often arid air mass with minimal chances for precipitation or even clouds. This happens due to the sinking air parcels in the center of the heat dome, resulting in rising temperatures. Sometimes, we see the weather pattern developing a so-called Omega blocking High.
The example below shows this kind of omega-blocking pattern over Europe from early September last year. The pattern engulfed a large part of the continent, with a central heat dome and a low-pressure system on each side. One low was over the southern Mediterranean, and the other over the Azores.
Especially during dry summer, drier and warmer weather produces a significantly enhanced wildfire threat due to developing drought. Or additionally worsening the ongoing, pre-existing, arid conditions. Such examples were wildfires in the Pacific Northwest and other parts of western North America in recent years or in Europe (Greece, Portugal, etc.) during last year’s summer season.
A heat dome is often also to blame for deadly heatwaves worldwide, as the scorching and excessive heat usually lasts for a very long period. Such heat dome events brought record temperatures in many countries worldwide in the summer of 2023, extending into the fall seasons.
The daily average, minimum, and maximum temperatures under the heat dome are typically significantly above average. When the heat dome is solid, it challenges existing historical records. This becomes particularly striking when this feature develops during early summer or autumn.
A heat dome and upper ridge over Southern Europe strengthen, heatwave intensifies and spreads north
Thanks to a persistent heat dome and blocking high across the southern half of Europe from the beginning of this month, the high-pressure system will build up across Central and Western Europe this weekend into early next week.
The warm plume above will allow the heatwave to intensify from Spain and Portugal into France, Benelux, and the UK by Monday next week. Heat will also spread and intensify over Germany, central Europe, and the Balkan peninsula.
The upper-level ridge is forecast to be the strongest this weekend into mid-next week, pushing temperatures in the lowest levels into the upper-30s across central France and surpassing 40s in the south and west parts.
From Sunday through Tuesday, the highest temperature anomaly is expected across France, western Germany, Benelux, and the southern UK. Temperatures will be around 10-12 °C above the average for mid-August.
The strengthening heatwave will allow temperatures to climb the most across France, Benelux, central Europe, most of Germany, Italy, and the Balkan peninsula.
The following chart indicates the 2 m temperature anomaly on Monday next week, with abundant heat underneath the heat dome and strong upper ridge aloft.
After Wednesday, the hottest air mass will gradually diminish as the ridge shifts towards the northeast. Still, temperatures will remain hot across the south and central parts of the continent at least until the next weekend.
Therefore, scorching heat will continue throughout Southern and Central Europe through mid-August.
The general temperature picture hints at the summer heat continuing to dominate the southern half of Europe through mid-August. According to global GFS and ECMWF weather models, it may extend further into the 2nd half of the month.
Below is a video animation of the heatwave’s redevelopment across Europe and its progress across Western Europe next week.
After mid-month, the overall weather model consensus also suggests that chances for rain and thunderstorms (including severe storms) will again be possible across western Europe. Meanwhile, the South and East remain more stable, hot, and dry. With the extreme wildfire threat worsening.
Peak temperatures will reach the low 40s in France, Spain, Portugal, Italy, and the Balkans. UK up to +33 °C on Monday
With the upper High gradually expanding and strengthening from the western Mediterranean towards Western Europe this weekend, temperatures will warm up again from Portugal and Spain into France, Germany, Benelux, and the UK.
Temperatures will also increase across Italy, the Balkan peninsula, and central Europe.
France, Benelux
From Sunday through Tuesday, peak afternoon temperatures are forecast to reach the upper 30s to low-40s across parts of France. Sunday will be the hottest in western and southwestern France, with peak afternoon temperatures around +42 °C.
Monday and Tuesday will also be very hot, with high temperatures reaching further north. On Tuesday, central and Northern France and Benelux will push into the mid- to upper 30s.
The highest temperatures on Tuesday could reach around +38 °C across northern France, including the capital, Paris.
Around 33-35 °C will spread across Benelux and western Germany.
UK
The summer heat will again spread throughout the UK early next week. Monday will be southern and central England’s hottest day of the year.
Daytime temperatures will reach the low to mid-30s across southern England on Monday. Further north and west into Scotland and Ireland, low 20s are forecast for a few days, but the hottest airmass will remain to the south.
Temperatures will remain above average after Tuesday but should peak around the mid-20s on most days.
Spain and Portugal
Excessive heat, with temperatures from the upper 30s to low 40s, will remain over the Iberian peninsula this weekend and next week. Through mid-August, scorching heat will continue across Portugal and Spain.
Multiple consecutive days will bring temperatures into the 40-43 °C range across southern and central Spain.
Later next week, southern Spain’s heat-prone lowland regions will likely experience temperatures close to +45 °C again.
Italy and the Balkans
The heatwave across the Mediterranean region and the Balkan peninsula is expected to continue through mid-August and into the second half of the month. The heat dome established aloft is strong and dominates southern Europe.
The forecast peak temperatures from Sunday through Wednesday next week suggest that parts of Italy, the south-central Balkans, and the Panonian plains will experience upper 30s to low 40s. Some areas could also challenge daily records.
According to long-range weather models, no significant temperature changes were foreseen across the southern half of Europe also later this month. A heat wave may extend until the end of August.
The Health Risks During A Heatwave
During an extended period of hot weather, generally surpassing +35 °C, it is physically challenging and presents an enhanced risk for health.
Sweltering weather, particularly in extended periods – heat waves – is uncomfortable but presents a significant health risk.
Who is most at risk?
Scorching hot weather is uncomfortable for most people. The following groups are particularly threatened by the very high temperatures we encounter during heat waves:
elderly people aged over 75 years
babies, young children
people with chronic/long-term health conditions, such as diabetes, respiratory disease, circulatory disease
People who are obese
People taking certain medicines
people who work outdoors, in hot/poorly ventilated areas, or engage in physical activity in hot weather
socially isolated people
people who are not acclimatized to hot weather, such as tourists from northern countries
Always stay cool, hydrated, and healthy in scorching hot weather
Staying hydrated is one of the most crucial things during extreme heat. Consider taking these precautions and measures to stay healthy in scorching weather:
Drink plenty of water! – A human’s body cools through sweating; on a sweltering day, an adult may lose up to several liters of water. Keep drinking water, and avoid drinking alcohol, hot drinks, and drinks with high sugar content, as they can worsen dehydration. Regular water intake is a good way of preventing dehydration.
Keep your body cool; stay out of the sun if possible. Eat small meals, preferably fruit, and salads. Wear light-colored and loose clothing made from natural materials like cotton. Take a cool shower or a cold bath if you feel hot. Also – keep your workspace and living space cool. If you do not have air conditioning, shut the curtains and blinds during the day. Stay in the coolest room, and avoid using the stove and oven as much as possible. If your home gets too hot, go to a cooler place – a library, shopping center, cinema, or swimming pool.
Keep your food safe! Properly Store food that needs refrigeration! Food spoils rapidly at high temperatures, and you may risk food poisoning if it is not stored correctly.
If you need to go out in the sun, protect your skin, use proper sunscreen and clothing to avoid sunburns and cover your head correctly.
Know your body and have a plan – Ask your doctor if you have any health conditions that may increase the risk of heat-related illness. Call and consult with your doctor if you are feeling unwell. Call emergency help (know the number!) if you feel unwell!
Common heat-related illnesses with symptoms: What to do if it happens?
WHO considers these symptoms’ descriptions and treatments below as informative only – consult with your doctor for details and professional advice:
Dehydration
Dehydration occurs when the body loses too much water to maintain normal functions. Symptoms include dizziness, tiredness, irritability, thirst, dark yellow urine, loss of appetite, and fainting. Drink plenty of water or diluted fruit juice. Avoid coffee, alcohol, and sugary drinks. Move to a cooler space to cool off. If you feel unwell, call your doctor or emergency room.
Heat rash
Heat rash is an itchy rash caused by excessive sweating. Move to a cooler, dryer environment, and keep the affected areas dry. Hydrating creams may make the condition worse. Consult with your doctor.
Heat cramps
This happens during strenuous activity when the body sweats and loses water and salt. Heat cramps manifest as muscle pains or spasms. If this happens, stop all activity, move/lie down in a cool place, and raise your legs slightly. Drink water or diluted juice. Have a cool shower or bath, and apply ice packs. Refrain from returning to strenuous activity for several hours. If heat cramps do not subside, seek medical help.
Heat exhaustion
Heat exhaustion is a condition caused by dehydration, which causes excessive loss of water and salt. Symptoms include heavy sweating, pale skin, fast and weak pulse, fast and shallow breathing, muscle weakness or cramps, tiredness and weakness, dizziness, headache, nausea or vomiting, and fainting.
If heat exhaustion occurs, the body needs to be cooled and rehydrated by moving to a chilled place, lying down, having a cool shower or bath, and placing cool packs under the armpits, groin, or back of the neck. Rehydration should be done by taking small amounts of cool fluids. Medical help is advised if symptoms do not abate within an hour.
Heat stroke
Heat stroke happens when the body temperature reaches 40.5 °C, a severe and life-threatening condition! Immediate first aid in lowering body temperature is critical, and an immediate call for an ambulance! Find more information on heatstroke here.
High relative humidity during a heatwave can also significantly affect the body, making it physically challenging for those working outside. After high rainfall, intense heating helps evaporate the soaked grounds, resulting in higher humidity than usual.
We use a heat index to represent the natural feel of scorching hot temperatures and high humidity. These graphics indicate the natural feel of temperatures based on the temperature and humidity.
As we see, when air mass has a temperature around +35 °C, humidity below 60 percent is much less challenging than once the humidity is very high, e.g., above 80 %. Thus, the actual feel temperature would be near 50 degrees Celsius.
Even at temperatures close to the 40s, such sweltering hot air becomes hard to handle with even lower humidity, 50 to 60 percent.
Wxcharts, Pivotalweather, and Wetterzentrale provided images for this article.
See also:
What does the South Pole Stratospheric Warming mean for Winter 2024/2025?
