SPECIAL WARNING
General Weather Evolution for the Next Days over the Ocean and Europe
Europe: Analysis & Forecast maps
Synoptic evolution across Europe – 27 August 2026
A marked deterioration in the weather is set to develop. A 995 hPa low-pressure system, moving into the northern North Sea on Friday, will drive a cooler, moist and unstable south-westerly airflow of Atlantic origin behind an active cold front. Frequent showers are therefore likely across Belgium.
During the weekend, another low of around 1001 hPa will move eastwards from the Atlantic across northern England before gradually filling towards southern Scandinavia. The associated frontal systems will bring the main spell of rain and showers on Saturday afternoon and evening. On Sunday, this unsettled weather will gradually give way to milder and relatively stable air spreading northwards from the southern Bay of Biscay.
At the beginning of next week, further Atlantic disturbances will continue to move eastwards across the North Sea, although their influence on Belgium should remain limited. At the same time, an anticyclonic ridge of 1020–1022 hPa extending from the Azores via the Bay of Biscay and France towards central Europe will promote a spell of more settled and pleasantly mild weather.
However, another rain-bearing disturbance could cross Belgium around the middle of next week. This would once again be followed by mild Atlantic air, as a 1025 hPa high-pressure cell becomes established over south-western France.
Probable weather evolution over Europe Likely trend (based on mid-tropospheric anomaly patterns)
https://www.bmcb.be/trend-europe-europa/
Synoptic outlook: 4–10 September 2026
Data updated on 27 August 2026
A broad area of low pressure over the Atlantic is expected to gradually expand north of the British Isles towards Scandinavia and Russia. At the same time, the area of high pressure dominating much of southern Europe, the Balkans and, initially, our regions should gradually weaken over western Europe as low pressure strengthens further across the British Isles and the North Sea.
This evolution would initially favour a south-westerly flow across our regions. Temperatures should remain relatively mild through 7 September, while rainfall is likely to remain limited, with only occasional weak disturbances or, in some areas, completely dry conditions.
From 7 September onwards, the change in the weather pattern should become more noticeable. Generally moderate Atlantic disturbances would progressively reach our regions, accompanied by a temporary influx of cooler air. Conditions would consequently become more unsettled and wetter, potentially marking the transition towards a more distinctly autumnal weather pattern.
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National Thermal Indicator
MULTIMODEL BMCB
(These forecasts are generally updated daily)
Thermal evolution — Update 26 August 2026
The Belgian national thermal indicator continues its upward trend towards a peak of +6 to +7, signalling maximum temperatures of 25 to 30°C for Thursday.
This final burst of warmth will nevertheless be short-lived. It will gradually give way to more unsettled conditions, with a succession of Atlantic disturbances crossing the country.
With the exception of 2 September, when the indicator is expected to fall between +1 and -1, with maximum temperatures of just 16 to 21°C, it should subsequently fluctuate between +1 and +4. Daytime temperatures will generally range from 19 to 26°C during the milder spells, and from 17 to 23°C during the less favourable periods.
In short, after one final summer flourish, the weather will gradually acquire a more Atlantic and distinctly autumnal character..
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Forecast for the coming days
Multimodel BMCB ( OPERATIONAL + ENSEMBLES ICON-GFS-ECMWF-AIFS-GCGFS )
Forecast of the range of temperatures, precipitations + general type of weather in Belgium
(These forecasts are usually updated daily)
Weather Evolution across Belgium — Update 26 August 2026
Based on the BMCB multi-model: operational models and ICON, AIFS and ECMWF ensembles
After an unsettled end to August, with mild, humid and frequently windy conditions, the weather should gradually become more settled at the beginning of September. Rain and showers will nevertheless remain frequent through Monday 31 August, before a more marked improvement on Tuesday.
Thursday 27 August
A fairly warm but unstable day. Sunny spells will alternate with showers, some of them heavy and potentially thundery. The afternoon will remain rather cloudy, with a few brighter intervals and showers, particularly near the French border. A moderate to fresh southerly wind will produce local gusts of 40–50 km/h. During the evening and overnight, rain and thunderstorms, locally intense, will cross the country before clearing after midnight.
Rainfall: 5–45 l/m².
Friday 28 August
Turning slightly cooler, although still fairly mild. Variable cloud, sunny intervals and showers, some potentially thundery and locally heavy, will occur throughout the day. The south-westerly wind will remain fresh, with gusts of 50–60 km/h.
Rainfall: 5–25 l/m².
Saturday 29 August
Still fairly mild, with variable to cloudy skies. Some light rain or showers are possible in the west. Showers will become more widespread overnight, gradually easing after midnight except along the coast. Fresh south to south-westerly winds will produce gusts of 50–60 km/h.
Rainfall: 0–10 l/m².
Sunday 30 August
Variable to cloudy with a risk of rain or showers, followed by a few passing sunny intervals during the afternoon. Fresh south-westerly winds will produce gusts of 45–55 km/h. It will remain mild, although a few moderate, locally thundery showers are possible overnight.
Rainfall: 0–20 l/m².
Monday 31 August
Another changeable day, with sunny spells alternating with showers, locally thundery. Showers will be most frequent in the west during the morning, then mainly across the north and east during the afternoon. South-westerly to westerly winds will strengthen, with local gusts reaching 65–75 km/h. Temperatures will remain fairly mild.
Rainfall: 2–25 l/m².
Tuesday 1 September
A marked improvement. After some cloudy intervals, brighter conditions will develop, with the afternoon becoming fairly sunny in places. Few or no showers.
Rainfall: 0–5 l/m².
Outlook for 2–8 September
The opening days of September are likely to become calmer and drier overall, with temperatures around or slightly above the seasonal average. Some periods of light to moderate rain or showers may still occur on 2 and 3 September.
From Friday 4 September, a drier spell is increasingly likely, with little or no rainfall. Temperatures may become very mild on Saturday 5, before easing slightly on Sunday 6. Mild conditions should then persist, with temperatures returning closer to seasonal levels on 7 and 8 September.
In summary: an unsettled, wet and windy end to August will gradually give way to calmer and drier conditions at the beginning of September. Temperatures should remain predominantly mild, with no indication at this stage of a significant outbreak of cold air.
SOURCE: METEOCONSULT
BENELUX:
Weather Outlook for 3-4 weeks
Weather Outlook – Update of 20 August 2026
4–13 September: settled and mild conditions
The outlook continues to favour settled, predominantly anticyclonic and relatively mild weather. Maximum temperatures could reach 20 to 27°C, generally around 1°C above seasonal averages.
Rainfall is expected to remain below average, with a fairly widespread precipitation deficit.
14–20 September: a return to warmer and drier conditions?
The various forecast scenarios are now increasingly pointing towards a gradual warming trend, with predominantly dry conditions continuing.
Temperatures could rise well above seasonal averages, suggesting the possibility of a return to summer-like conditions during the second half of September.
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Weather Outlook for 3 months
Autumn 2026 Outlook — Update 11 August
An autumn that could prolong the summer
Autumn 2026 is expected to remain generally warmer than normal. The strongest and most robust signal is currently centred on September, which could bring genuine extensions of summer. Milder-than-average conditions should then remain dominant through October and November, although the temperature anomalies are likely to become progressively less pronounced.
As far as rainfall is concerned, the scenario of persistent drought lasting into October now needs to be qualified. September could still remain dry in some areas, but Atlantic disturbances are expected to become increasingly frequent as the autumn progresses.
Such rainfall would be particularly welcome after this summer's drought. A more regular return of precipitation in November could begin to improve the hydrological situation, although the substantial deficits accumulated during the dry period would not necessarily be replenished quickly.
There is, however, a potential downside. After a prolonged period of severely dried-out soils, the return of heavy rainfall could increase the risk of rapid runoff and localised flooding. The weather pattern could therefore gradually swing from an excess of dryness to an excess of water.
September: summer refuses to leave
September currently carries the strongest warm signal, with temperatures potentially around 1.5°C above the seasonal average at national level.
Late-season heat spells therefore remain quite possible, particularly during the first half of the month. Summer could, at times, appear reluctant to give way to autumn.
Rainfall, however, is still expected to remain below normal in some regions, prolonging locally the hydrological difficulties inherited from the summer.
October: mild conditions remain dominant
October is also expected to be generally mild, with a temperature anomaly currently estimated at around +1°C.
High-pressure periods could once again bring some fine, bright and pleasantly mild days, although Atlantic disturbances should gradually become more frequent.
At present, there is no strong indication of either an exceptionally dry or an especially wet month. Rainfall is more likely to remain close to seasonal averages.
November: wetter, but still mild
The warmer-than-average signal is expected to persist into November, although in a more moderate form, with temperatures around 1°C above normal.
A transition towards a more oceanic weather regime is becoming increasingly plausible. Atlantic disturbances could then track more regularly across France and into our region, bringing more frequent rainfall.
Rainfall totals could consequently return to around normal levels, or even become slightly above average.
In summary: after a summer marked by heat and drought, autumn could initially continue in a distinctly summery vein before gradually taking on a more Atlantic and wetter character. Mild conditions look set to remain the common thread throughout the season, while the expected return of more regular rainfall in November could finally begin to ease the hydrological deficit. After such prolonged dryness, however, heavy rainfall would also bring an increased risk of runoff and flooding.
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from ICON (replace location left above )
from ECMWF (replace location left above)