Spanish weather agency forecasts unseasonal warmth up to 35 °C as summer conditions extend into autumn

Late heat wave across the peninsula

Spain will experience a widespread rise in temperatures over the weekend as a warm air mass displaces cooler air across the Iberian Peninsula. According to forecasts from the State Meteorological Agency (AEMET) and Meteored, daytime highs will sit between 5 and 10 degrees Celsius above seasonal norms across broad areas of the interior and the north. Thermometers in northern autonomous communities, including Galicia, Asturias, Cantabria, the Basque Country, and northern Castile and Leon, will register sharp jumps of 6 to 8 degrees Celsius compared to previous days. By Sunday afternoon, the thermal episode will reach its peak intensity, bringing summer conditions across central, western, and southern regions just days before the official arrival of autumn.

Storm alerts and coastal winds on Saturday

Before broad atmospheric stability establishes itself over the mainland, residual instability will generate localized storms across the eastern Mediterranean coast and the Balearic Islands on Saturday. AEMET has activated yellow warnings for heavy showers and thunderstorms in the southern coastline of Valencia, northern Alicante, the Pitiusa islands of Ibiza and Formentera, and sectors of Murcia including Lorca, Aguilas, and the Campo de Cartagena. Meanwhile, the Strait of Gibraltar and the Cadiz coastline will face strong Levante winds and high waves, with yellow warnings extending into Sunday across the Cadiz countryside. In the Canary Islands, the weekend will remain calm under trade winds, bringing cloudy skies and light showers only to mountainous northern zones.

Regional maximums and tropical nights

Thermometers will rise consistently across southern and western river valleys throughout the weekend. On Saturday, maximums will exceed 34 degrees Celsius in cities such as Badajoz, Cordoba, and Seville, while southern Galicia, Toledo, and Caceres will reach between 30 and 32 degrees Celsius. By Sunday, Seville and depressions in the southwest will see highs of 35 degrees Celsius, while Cordoba, Badajoz, and the Mino Valley cities of Ourense and Pontevedra will hit 34 degrees Celsius. The Community of Madrid will reach 32 degrees Celsius in municipalities such as Alcala de Henares, with minimums in the Sierra rising to 17 degrees Celsius. Along the southern Mediterranean coast and the lower Guadalquivir, nighttime temperatures will stay elevated in tropical nights, contrasting with potential weak frosts on high Pyrenean ridges.

So we can say that in the week when astronomical autumn begins, it will do so with summer weather.

Outlook for the autumn equinox

Stable, sunny conditions will dominate the peninsula through the start of the following week, consolidating the late summer pattern. In Catalonia, weather will stabilize with highs reaching 30 to 32 degrees Celsius in inland districts and Ponent, following mid-week storms that previously dropped 100 millimeters of rain in areas like Garraf and Valles Occidental. From Monday, September 21, maximum temperatures will remain above 30 degrees Celsius across wide stretches of the Spanish interior, climbing between 32 and 34 degrees Celsius by Tuesday and Wednesday. The astronomical autumn equinox on September 23 will consequently arrive with dry skies and persistent warmth across the country.