After an already unseasonably mild week, Luxembourg is expected to see temperatures climb even higher at the start of next week. Weather forecasts from several sources indicate that highs could approach, or even briefly exceed, 30°C, which is a striking anomaly for this time of year that underscores just how far September 2026 has strayed from the country’s traditional climate norms.
On Saturday, subtropical air masses will continue to dominate, although skies will be more variable than in recent days, particularly in the west where high clouds are expected. Temperatures will range from 17°C to 23°C in the west, climbing to between 20°C and 25°C in the south and along the Moselle.
Sunday will see the return of increasingly sunny conditions. Some early morning fog patches are likely in central areas, but these are expected to clear quickly. Maximum temperatures will then rise further, reaching between 23°C and 26°C.
A minor disturbance will attempt to push in from the French border on Monday, but high continental pressure should largely keep it at bay. As a result, the south and west may experience more clouds, perhaps with some patchy light rain, while the east should continue to enjoy sunny spells. Temperatures will remain well above seasonal norms, with highs between 20°C in the west and 27°C in the east.
Tuesday is set to be the hottest day of this period. Sunshine will prevail, interrupted only by decorative high clouds. A south-easterly wind, gusting up to 40–45km/h, could accompany soaring temperatures, with highs between 26°C and 30°C, and even slightly higher in the most sheltered areas. Such values are extremely rare for late September and align with historical records for unusually warm spells at this time of year.
By Wednesday, clouds will begin to move in from the west, but dry weather is expected to persist for most of the day. Temperatures will remain exceptionally high, ranging from 24°C to 30°C, before an active weather front approaches in the evening.
Thursday will mark a shift in the weather pattern as the approaching front brings several hours of steady light rain. Skies will then begin to clear from the west as the day progresses, with temperatures dropping sharply behind the front and settling between 18°C and 23°C.
By the end of the week and into early October, Luxembourg is expected to see a return to more typical autumn weather. Occasional scattered showers and frequent sunny spells will be the norm, with daytime highs between 16°C and 21°C, and cooler nights dropping to around 5°C to 10°C under clear skies.
