High pressure over Europe: sunshine above, fog below
A high of 1033 hPa settles over the North Sea on Friday. In the mountains the sun shines, in the valleys the fog may last all day.
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Large parts of Europe are heading into a period of increasingly settled autumn weather. However, high pressure does not necessarily mean blue skies and sunshine. In fact, the coming days could bring one of autumn's most characteristic weather patterns: persistent fog in the valleys and lowlands, while the mountains enjoy glorious sunshine and surprisingly mild temperatures.
While the deep Atlantic lows remain to the northwest, high pressure is becoming increasingly influential across much of the continent.
For Friday, 30 October, our model puts a high-pressure centre of around 1033 hPa over the North Sea, more precisely over the German Bight. From there the settled air reaches far to the west and into central Europe.
The high then strengthens further: by Sunday, 1 November, the central pressure west of Scotland rises above 1040 hPa. A European high does not reach that level every year.
The video shows how the high settles over Europe from Friday to Sunday.
For many regions this means less unsettled weather, lighter winds and a much lower chance of rain.
But there is a catch.
In late October and November, the situation is often very different.
The reason is a combination of long nights, weak sunshine, moist air and a process known as a temperature inversion.
Under high pressure, winds are usually light and skies clear overnight. The ground then loses heat and cools the air immediately above it.
If that air cools to its dew point, the water vapour condenses into tiny droplets and fog or low cloud forms.
At the same time, air within the high sinks on a large scale and warms at higher levels.
The result is a temperature inversion: instead of getting colder with height, a layer of warmer air sits above the cold air near the ground.
That warm layer acts like a lid. It prevents mixing and traps the cold, moist air in valleys and low-lying areas.
Once the fog is there, the weak autumn sunshine is often not enough to clear it.
In some places it stays all day.
In the mountains, above the inversion: conditions can be beautiful. Bright sunshine, excellent visibility and surprisingly mild daytime temperatures. Standing above the fog, you look out across a vast sea of clouds. In sunny, sheltered spots it can even be warmer up there than in the valley below.
In the valleys and lowlands, beneath the inversion: the same day feels like a different season. Persistent fog, low cloud, high humidity and chilly temperatures dominate. In some places visibility stays poor and the sun never breaks through at all.
The contrast is most pronounced in river valleys, inland basins and sheltered lowlands.
A mountain village can enjoy a mild afternoon in full sunshine while a town a few hundred metres lower stays grey and cold. Both lie within the same high.
Forecast values for Friday, 30 October 2026, from the ICON-EU run of 28 October, 00 UTC.
In Vitoria, visibility stays below one kilometre on three consecutive days. Southern Spain, by contrast, lies on the sunny side of the very same high, with almost 25°C in the Guadalquivir valley.
Visibility can drop sharply at night and in the early morning, especially on motorways crossing valleys, plains and river basins.
In some places the fog stays dense well into the afternoon.
Allow extra time, slow down when visibility is poor and use appropriate lighting.
Fog can also affect airport operations. Whether there are actual delays depends on visibility and conditions at each airport.
Anyone heading into the mountains, on the other hand, will often find far brighter weather above the fog layer.
Pressure alone, however, does not tell you whether a particular place will be sunny or foggy.Our forecasts are updated four times every day.
For some they will mean sunshine, clear mountain air and a view above the clouds.
For others, grey skies, persistent fog and chilly afternoons.
The important point: in autumn, high pressure is no guarantee of sunshine.
And sometimes a few hundred metres of altitude decide whether the day is gloomy or glorious.
Weather you can understand. Information you can trust.
Forecast basis: pressure guidance from the ICON model and visibility and cloud forecasts from ICON-EU, shown on meteo365.es, runs of 28 October 2026, 00 UTC. This article describes a developing weather pattern, not a location-specific fog warning. Details may change with subsequent model runs.
High pressure spreads across Europe
Our latest ICON forecasts at meteo365.es show a significant change in Europe's pressure pattern.While the deep Atlantic lows remain to the northwest, high pressure is becoming increasingly influential across much of the continent.
For Friday, 30 October, our model puts a high-pressure centre of around 1033 hPa over the North Sea, more precisely over the German Bight. From there the settled air reaches far to the west and into central Europe.
The high then strengthens further: by Sunday, 1 November, the central pressure west of Scotland rises above 1040 hPa. A European high does not reach that level every year.
The video shows how the high settles over Europe from Friday to Sunday.
For many regions this means less unsettled weather, lighter winds and a much lower chance of rain.
But there is a catch.
Why high pressure produces persistent autumn fog
In summer, high pressure usually brings long, sunny and warm days.In late October and November, the situation is often very different.
The reason is a combination of long nights, weak sunshine, moist air and a process known as a temperature inversion.
Under high pressure, winds are usually light and skies clear overnight. The ground then loses heat and cools the air immediately above it.
If that air cools to its dew point, the water vapour condenses into tiny droplets and fog or low cloud forms.
At the same time, air within the high sinks on a large scale and warms at higher levels.
The result is a temperature inversion: instead of getting colder with height, a layer of warmer air sits above the cold air near the ground.
That warm layer acts like a lid. It prevents mixing and traps the cold, moist air in valleys and low-lying areas.
Once the fog is there, the weak autumn sunshine is often not enough to clear it.
In some places it stays all day.
Two completely different autumn days, a few kilometres apart
This is what makes high pressure in autumn so fascinating.In the mountains, above the inversion: conditions can be beautiful. Bright sunshine, excellent visibility and surprisingly mild daytime temperatures. Standing above the fog, you look out across a vast sea of clouds. In sunny, sheltered spots it can even be warmer up there than in the valley below.
In the valleys and lowlands, beneath the inversion: the same day feels like a different season. Persistent fog, low cloud, high humidity and chilly temperatures dominate. In some places visibility stays poor and the sun never breaks through at all.
The contrast is most pronounced in river valleys, inland basins and sheltered lowlands.
A mountain village can enjoy a mild afternoon in full sunshine while a town a few hundred metres lower stays grey and cold. Both lie within the same high.
Where the fog sits, and where it does not
How big the difference becomes is shown by our forecast for Friday. Visibility is the lowest value of the morning, the temperature is the daytime maximum.| Location | Visibility, morning | Maximum |
|---|---|---|
| Vitoria, Basque Country | 0.2 km | 15.7°C |
| Burgos | 1.2 km | 16.4°C |
| Munich | 2.4 km | 10.5°C |
| Zaragoza, Ebro valley | 15.2 km | 20.6°C |
| Andújar, Guadalquivir | 24.7 km | 24.7°C |
| Granada | 32.1 km | 23.6°C |
| Sierra Nevada, 2,100 m | 41.8 km | 14.3°C |
In Vitoria, visibility stays below one kilometre on three consecutive days. Southern Spain, by contrast, lies on the sunny side of the very same high, with almost 25°C in the Guadalquivir valley.
Travel weather: fog is the real challenge
For travellers, persistent autumn fog deserves particular attention.Visibility can drop sharply at night and in the early morning, especially on motorways crossing valleys, plains and river basins.
In some places the fog stays dense well into the afternoon.
Allow extra time, slow down when visibility is poor and use appropriate lighting.
Fog can also affect airport operations. Whether there are actual delays depends on visibility and conditions at each airport.
Anyone heading into the mountains, on the other hand, will often find far brighter weather above the fog layer.
Follow the development with meteo365.es
Our pressure charts show how the high builds across Europe between Wednesday and the start of November.Pressure alone, however, does not tell you whether a particular place will be sunny or foggy.Our forecasts are updated four times every day.
Autumn has two faces
The coming days could become a textbook example.For some they will mean sunshine, clear mountain air and a view above the clouds.
For others, grey skies, persistent fog and chilly afternoons.
The important point: in autumn, high pressure is no guarantee of sunshine.
And sometimes a few hundred metres of altitude decide whether the day is gloomy or glorious.
Weather you can understand. Information you can trust.
Forecast basis: pressure guidance from the ICON model and visibility and cloud forecasts from ICON-EU, shown on meteo365.es, runs of 28 October 2026, 00 UTC. This article describes a developing weather pattern, not a location-specific fog warning. Details may change with subsequent model runs.
