Yet another Heat Dome is developing in Europe, the 6th powerful heatwave of the season. The primary atmospheric engine behind this late-summer thermal surge is a stubborn blocking high-pressure system parked over the Central Mediterranean and Southern Europe.
As sinking air adiabatically compresses and warms the lower troposphere, peak afternoon surface temperatures across low-lying river basins and plains are forecast to range from 38 °C to 43 °C, with dry continental winds accelerating soil moisture loss.
This prolonged thermal surge offers minimal nocturnal relief, as overnight low temperatures refuse to drop below 22 °C to 26 °C in major urban corridors. The lack of nighttime cooling compounds severe physiological stress for millions of residents, skyrockets energy grid demand, and significantly heightens explosive wildfire conditions across southern and central European valleys.
The strongest temperature anomalies are forecast across Southern and Central Europe throughout the rest of this week, projected to gradually vanish from west to east over the following weekend. The following chart shows the mid-range forecast for Rome, Italy, and Belgrade, Serbia.
Temperatures across Italy and the central Balkans are forecast to peak in the low-40s this week, and will be highest from Thursday through Saturday.
Forecast model animation maps below illustrate the expansion of this upper-level ridge into South-Central Europe and highlight where the highest 850 hPa temperature anomalies will focus over the coming days.
Before we dig into the details, let’s examine what a heat dome is and why understanding its dynamics matters.
Atmospheric Dynamics: How High-Pressure Heat Domes Compress and Trap Air
When significant, record-breaking heatwaves occurred in the United States, Canada, and Europe in the past, heat domes contributed. Heat domes are usually the dominant feature of summer weather patterns on both continents.
We call this phenomenon a heat dome when extremely high temperatures develop. Here’s how it works and why understanding it on a broader scale is essential. The upper-level ridge pattern, or very warm air mass in the higher altitudes, also known as the Upper High (or blocking High), usually forms the heat dome. This weather pattern brings high, and sometimes record-breaking, temperatures to the region below.
This term is used when a broad area of high-pressure air parks over a large portion of the continent. If the event is remarkably stable and extreme, it usually lasts several days or weeks.
The heat dome works like a lid on a pot. The extensive dome traps warm air at all levels underneath, with layers sinking toward the ground. As a result, the air mass becomes anomalously warm at the lowest elevations and extremely hot near the surface.
Health and Grid Impacts: Managing Nocturnal Heat Stress and Heat Index Extremes
Excessive heat in heat domes can significantly impact human health and be dangerous to particularly vulnerable populations, such as elderly individuals, children, and those with pre-existing health conditions that can be worsened by extreme heat.
Due to prolonged exposure to high temperatures, construction workers, farmers, and other long-hour outdoor workers are at increased risk of heat-related illnesses. People living in poverty are also more susceptible to the fatalities of heat domes, as their houses are often built with heat-trapping surfaces such as concrete and asbestos.
Heat exhaustion occurs with prolonged exposure to high temperatures. It leads to dehydration and dizziness, and in more severe cases, it can progress to heat stroke.
High relative humidity during a heatwave can also significantly affect the body. For this reason, we use the Heat Index to represent the perceived feel of scorching-hot temperatures and high humidity. It illustrates the natural relationship between temperature and humidity.
When the air mass has a temperature around +35 °C, humidity below 60 percent is much less challenging than when the humidity is very high, e.g., above 80 %. Thus, the actual feel temperature would be near 50 degrees Celsius. Heat waves have also been associated with increased rates of heart attacks, strokes, and respiratory illnesses.
Our additional article, Health risks during a heatwave and sweltering hot weather, provides further details on the health risks.
Beneath these staggering meteorological statistics lies an even more grim threat. The danger is magnified by suffocating so-called ‘tropical nights’ where temperatures don’t drop below 24 °C, denying the human body its vital window to cool down.
Synoptic Setup: 6th Heat Dome Builds Across Southern and Central Europe
The general weather picture over the European continent this week indicates that a strong upper-level ridge is moving into the Mediterranean region from North Africa, gradually expanding into Central Europe and the Balkans. A major Heat Dome develops and dominates the continent.
An unseasonably strong and deep wave over the Bay of Biscay and western Iberia also helps the North African ridge to expand northward until the following weekend. Another large ridge sits over northern Europe.
The warmest air mass is trapped underneath the core of the heat dome aloft, spread across the Mediterranean, Italy, and Central Europe until Friday. The most anomalous temperatures will be over Italy and the central Mediterranean on Thursday.
The deep wave over the Bay of Biscay delivers significantly colder Atlantic maritime airmass into Portugal and western Spain, while also allowing this strong Mediterranean warm plume to push higher temperatures into Western Europe, including the UK and Benelux.
By Friday night, the upper-level wave from the Atlantic vanishes while the upper ridge over the Mediterranean and Central Europe remains powerful and stable. The heat dome becomes more elongated as it shifts from Central Europe and the Balkans also towards Eastern Europe through Saturday.
The heatwave covering Italy, the Balkans, and Central Europe will be unusually intense for the end-of-August period. This will bring significantly higher temperatures than recently over Italy, Bosnia, Serbia, Croatia, and Hungary.
As the heat dome gradually strengthens, the surface heatwave will bring the highest temperatures from the central Mediterranean into Central Europe and most of the Balkan Peninsula throughout the second part of the week.
The 2m temperatures will be around 12 to 16 °C above the long-term thermals for the end of August.
By the weekend, the excessive heat expands further east and northeast as the heat dome elongates and shifts east from Central Europe. This will allow temperatures to climb significantly over the Balkans, western Ukraine, and Poland.
Meanwhile, in the west, a maritime air mass from the Atlantic will gradually spread into western and southwestern Europe and bring refreshment for many countries.
Daytime Highs: Regional Breakdown of 40°C+ Temperature Extremes
Southern Europe: Italy and central Balkans peak near 42-43 °C on Friday, Greece nears the 40s
Until Friday, the hottest air mass will remain over the Mediterranean, gradually surging north into Central Europe and the Balkan Peninsula. Temperatures will be back into the upper 30s to low 40s across parts of Italy and north-central and southern Balkan countries, challenging some end-of-August daily highs locally.
The hottest air mass will be over the Po Valley in northern and southern Italy, eastern Croatia, Hungary, and northern Serbia (Pannonian plains), and Bosnia and Herzegovina in the north-central Balkans.
Central Europe: Temperatures from 32 to 36 °C over the Alpine region and Germany on Thursday
For a short period, the warm plume associated with the Mediterranean heat dome will push hot temperatures across the Alps into Germany on Thursday. The highest temperatures will reach the low to mid 30s locally, while Friday will already deliver lower temperatures as a maritime air mass spreads from the west.
Friday and Saturday will remain hot across Central Europe, into the Czech Republic and Slovakia, while the heatwave from the south penetrates towards Poland and Ukraine over the weekend.
Lower temperatures will gradually spread across Western and southwestern Europe before the weekend arrives.
Thursday delivers a potential severe thunderstorm outbreak for France and the western Alps
This week’s weather pattern over Europe shows the underlying risk to France on Thursday. As a strong upper-level ridge builds over the Mediterranean, Central Europe, and the Balkans, a deep wave over western Iberia creates a significant pressure and temperature gradient between the two large-scale features.
This significantly amplifies southwesterly jet-stream winds from eastern Spain across the western Mediterranean into southern and eastern France, providing violent wind shear.
The left-exit jet region hints at a widespread forcing for organized severe weather.
Instability will be high to extreme, thanks to a historic maritime heatwave that has established across the Mediterranean this summer. 3000 to nearly 5000 J/kg of potentially available convective energy (CAPE) will fuel thunderstorms from the Western Mediterranean.
The overlap of extreme instability and strong vertical wind shear will promote explosive development of organized severe weather, including intense supercell thunderstorms, capable of producing very large to giant hail, tornadoes, severe winds, and torrential rainfall.
We will continue to monitor the evolution of the weather pattern and update the forecasts accordingly. Long-term trends suggest the pattern will remain dynamic and warm further into early September, starting the following week. Stay tuned for updates.
PivotalWeather and WXcharts provided images used in this article.
See also:
Fall 2026 Forecast Update: Super El Niño Builds a Split-Flow Pattern Ahead of Winter 2026/2027