Spain’s summer heat is set to end as a strong Atlantic storm moves toward the peninsula and could arrive this weekend. Meteorologists warn that explosive cyclogenesis, a rapid drop in pressure, may be underway. Spain has entered astronomical autumn, but the heat has not let up: the summer of 2026 was the hottest since at least 1869, information from Spain’s meteorological agency AEMET and the Ministry for Ecological Transition. The national average temperature reached 24.5°C, 2.4°C above the 1991 to 2020 average.
For days, a stubborn anticyclone has kept the Iberian Peninsula under clear skies. Daytime highs have reached 37ºC in Córdoba, Sevilla and Ourense. Even as September ends, the Guadalquivir and Guadiana valleys are still facing temperatures close to 40ºC, more typical of July than autumn. AEMET called it a "four-month summer," with extreme heat lasting well beyond the usual season. Spain experienced 61 days this summer with conditions meeting the criteria for heat waves, AEMET reports.
Friday and Saturday will still feel like summer across much of Spain. The anticyclone will hold, with only small temperature drops in the northwest. Strong easterly winds will blow through the Strait of Gibraltar and the Canary Islands, while light, shifting breezes affect the rest of Spain. In the northern Canary Islands, clouds and showers may interrupt the clear skies.
The pattern is expected to break as a deep Atlantic low-pressure system moves in from the northwest. It could undergo explosive cyclogenesis, with basic pressure dropping by 20 hPa in just 24 hours. These storms can bring heavy rain and strong winds, with big waves especially likely in northern Spain.
By Sunday, the change will begin to show. Clouds will build over Galicia and the Cantabrian coast, with rain likely in all four Galician provinces, Asturias, La Rioja, Álava, Vizcaya and Guipúzcoa. The Atlantic front will move east, bringing showers to other northern and western areas. The Mediterranean coast and the Canary Islands will see some low morning clouds, while the western Canary Islands could get light rain.
As the storm deepens, temperatures will fall quickly. Highs will drop sharply in Galicia and the Cantabrian regions, while nighttime lows on the northwestern plateau will fall below 10ºC. The Pyrenees could see the first frosts, a marked change after September’s hot days.
AEMET’s official autumn outlook puts the probability of a warmer-than-normal autumn in Spain at 60% to 70%, compared with a 10% chance of a colder season. It gives a 40% likelihood of above-average rainfall in the north and east of the peninsula and on the Balearic Islands.
The basic change is expected on Monday and Tuesday, when meteorologists forecast that the Atlantic low will strengthen quickly and send waves of rain across the peninsula. The heaviest rain will fall on the Atlantic and Cantabrian slopes. Only a few Mediterranean spots may briefly reach 30ºC. By the end of the period, nighttime lows on the northwestern plateau will be close to single digits, and the first frost will appear in the high mountains.
