Spain on yellow alert as temperatures hit 38°C, tropical nights set in and severe thunderstorms threaten the northwest

Heat dome drives record temperatures

A potent anticyclone settled over Spain on Saturday 13 June 2026, triggering a widespread heatwave with yellow weather warnings across ten autonomous communities. Aemet forecast afternoon highs of 37 to 38 degrees Celsius in the Guadiana and Guadalquivir valleys, with Badajoz expected to reach 39 degrees. In the north, a sharp thermal rise (more than 6 degrees above previous days) pushed temperatures past 34 degrees in the Cantabrian interior, with Bilbao approaching 35 degrees. Cities like Salamanca and Zamora were forecast to hit 36 degrees, while Valladolid saw 35. The event, just days before the official start of summer, felt more like August than mid-June, as La Razón observed.

That cool spell we were having these June days is over. We're back to full summer weather.

Nighttime offers little relief

Minimum temperatures will remain elevated, with "tropical nights" (defined as lows not falling below 20 degrees Celsius) expected in the river basins of the southwest and along the entire Mediterranean coast. In capital cities like Salamanca, the overnight low was forecast at 19 degrees, while Burgos registered only 12. The southwest coastal areas and the Strait of Gibraltar will also experience moderate to strong easterly winds (Levante), with very strong gusts during the first half of the day, though easing later.

Thunderstorms and hail in the northwest

Despite the anticyclone's dominance, afternoon heating will generate convective clouds over the northwest quadrant. Aemet warned of locally strong thunderstorms with hail and very strong wind gusts in Galicia, western Asturias, and the provinces of León and Zamora in Castilla y León. "There will be showers accompanied by storms and very strong wind gusts, especially on Sunday," said Aemet spokesperson Rubén Del Campo. The storms, fueled by heat and a pocket of cold air aloft, could cause sudden visibility drops and hazardous road conditions.

There will be showers accompanied by storms and very strong wind gusts, especially on Sunday.

Fire and UV risk escalates

The combination of extreme heat, low humidity, and high insolation pushed the wildfire spread index to very high or extreme levels, particularly in the western half of Castilla y León. Authorities issued warnings for public caution, as the ultraviolet radiation index was also forecast to reach level 9 (very high). Officials urged residents to stay hydrated, avoid outdoor activities during peak hours, and protect themselves from the sun.

Sunday to bring further storms and continued heat

The unstable pattern will persist into Sunday, as cooler air at altitude interacts with surface heat to produce afternoon showers and storms inland, particularly over Castilla y León and Castilla-La Mancha. While the storms may not be severe, they will disrupt what otherwise remains a summer-like weekend. Aemet expects maximum temperatures to stay elevated (reaching 38 degrees in the central Ebro valley and 35 across the northeast and interior south) before a slight cooling on Monday, though values will remain high for the season.