Polar air mass to bring 10-degree temperature drops and heavy storms across Spain

Polar front brings unseasonal temperature drop

A polar air mass and an upper-level trough crossing the Iberian Peninsula will introduce autumn-like conditions across Spain through the weekend of 22–23 August 2026. Following days of persistent heat where parts of Valencia and the Balearic Islands exceeded 40 °C, the State Meteorological Agency (AEMET) projects temperatures to fall between 5 and 10 °C below normal values for late August. Northern and interior cities will experience the sharpest declines, with daytime highs remaining below 30 °C. Nighttime minimums will drop to 9 °C in León on Friday and 10 °C in Soria on Saturday, while Burgos and Salamanca are forecast to reach 11 °C. Castellón is expected to be the main exception to the cooling trend, with maximum temperatures remaining near 40 °C.

Heavy rainfall and severe storm alerts

The atmospheric shift will produce intense showers and convective storms across the northern and eastern sectors of the peninsula. AEMET warned that rainfall rates could reach 40 litres per square metre within one hour in parts of the northeast, creating localized flooding hazards in valleys and ravines. Forecasters also anticipate severe storm cells in the southeastern third of the mainland, capable of generating large hail and sudden convective downbursts. In the Balearic Islands, storm activity will peak during Friday morning across Mallorca and Menorca, where forecasters have not ruled out hurricane-force wind gusts. Precipitation in the Cantabrian region will gradually diminish in strength as Friday progresses, while heavy downpours will affect the southern coast of Catalonia during the afternoon.

AEMET spokesperson José Luis Camacho explained the wider atmospheric pattern behind the abrupt arrival of cool air.

This storm is within the normal range; what was not normal was what we had until now.

Record summer heat precedes the front

The cold front follows a summer marked by extreme temperatures in Spain. Meteorological records show that June 2026 was the second-warmest June on record, while July registered as the warmest single month in the national data series. Mar Gómez, director of the meteorology team at eltiempo.es, noted that 2026 is on track to rival the record set in 2025, which concluded with a nationwide average temperature of 24.2 °C and a positive anomaly of 2.1 °C. Camacho stated that while August has experienced severe heat, the incoming cooler air mass may prevent the month from reaching the anomalous highs seen in preceding weeks. The substantial energy accumulated in the Mediterranean Sea during the prolonged heatwave contributes directly to the severity of the expected storm systems.

Outlook for the weekend and early next week

Unsettled weather will persist into the weekend as a second trough settles to the west of the Iberian Peninsula. On Saturday, localized heavy showers and thunderstorms will concentrate across southern Catalonia, eastern Aragon, northern Valencia, and the central Pyrenees. On Sunday, rainfall and storm activity will continue to affect the northeastern peninsula and the Valencian Community. José Antonio Maldonado, meteorology director at Meteored Spain, reported that European forecast models indicate the low-pressure system could intensify on Monday, 24 August 2026. Such deepening would bring renewed rain and storms across northern Spain, though forecasters emphasize that early-week projections still carry significant uncertainty.