Spain’s national meteorological agency AEMET has issued weather warnings across eight autonomous communities as a cold air mass moving into the upper atmosphere triggers widespread instability following recent high temperatures. Andalucía, Asturias, Cantabria, Castilla y León, Castilla-La Mancha, Extremadura, Galicia and the Community of Madrid are all under yellow-level alerts for thunderstorms. Storm development is expected to start primarily during the afternoon and evening of Monday 15, when surface heating is strongest. Forecast conditions include heavy downpours, hail and strong wind gusts in affected areas.
The storms are expected to be unevenly distributed, with some localities experiencing intense rainfall while neighbouring areas remain largely unaffected. Monday June 15: storms intensify across central and western regions On Monday, thunderstorm activity is expected to become more organised across central and western Spain as atmospheric instability persists. The most affected areas include the Central System mountain range, the Cantabrian Mountains, the Iberian System and parts of Galicia and Extremadura. Meteorologists expect storms to form again during the afternoon, driven by continued interaction between
warm surface air and colder air aloft. Rainfall may be short in duration but heavy in intensity, increasing the risk of localised flooding in low-lying areas and river valleys. Road conditions are expected to be particularly affected during peak storm hours due to sudden reductions in visibility and surface water accumulation. Authorities have advised caution on rural and secondary roads in mountainous zones. Meanwhile, heat warnings remain active in Aragón, Cataluña, Navarra, La Rioja and the Basque Country, where temperatures may still reach between 36°C
and 38°C. The coexistence of extreme heat in the north-east and storm activity across the interior is contributing to highly unstable atmospheric conditions across the Iberian Peninsula. Tuesday June 16: continued convective storms in afternoon peak hours By Tuesday, AEMET forecasts continued convective storm development across large parts of central and northern Spain. The pattern remains consistent, with the most active periods expected during the afternoon and early evening. The highest risk areas remain the mountainous interior, including the Central System and surrounding provinces, as
well as parts of northern Spain influenced by Atlantic humidity. Storm cells are expected to form rapidly and may include hail, lightning activity and gusty winds. Rainfall distribution is expected to remain highly irregular, with sharp contrasts over short distances. Some areas may see minimal rainfall, while others experience intense, localised downpours within a short timeframe. Emergency services are monitoring river basins and steep terrain due to the potential for rapid surface runoff. Although widespread flooding is not forecast, isolated flash flooding events cannot be
ruled out where storms stall or repeatedly track over the same location. Wednesday June 17: gradual easing but isolated storms persist On Wednesday, atmospheric conditions are expected to begin stabilising gradually, although residual instability will still allow for isolated thunderstorms, particularly in elevated inland areas and mountainous regions. Any storms that do form are expected to be less widespread than earlier in the week, but may still produce locally heavy rainfall and brief periods of strong wind. Conditions are expected to improve more noticeably in
western regions first, while eastern inland areas may retain some convective activity into the afternoon. Overall, AEMET indicates a reduction in storm coverage compared with Monday and Tuesday, marking a transitional phase as the cold upper-level air mass weakens and atmospheric conditions begin to stabilise. Areas most at risk and expected impacts Throughout the period, the most affected zones include the Cantabrian Mountains, the Central System, the Iberian System, the Sub-Baetic ranges, Galicia, Extremadura and parts of the eastern Pyrenees. These areas are particularly vulnerable
to rapid storm formation due to orographic lift and localised convection. The primary risks include sudden heavy rainfall, hail, strong wind gusts and temporary flooding in low-lying or poorly drained areas. Transport disruption is possible during peak storm hours, particularly on rural roads and mountain passes. Meteorological cause of the instability AEMET attributes the weather pattern to a cold air mass entering upper levels of the atmosphere over the Iberian Peninsula, contrasting sharply with warm surface conditions left after several days of heat. This temperature
gradient is generating strong atmospheric instability and promoting convective storm development across large parts of Spain. The agency notes that such patterns are typical in early summer, when residual heat and incoming upper-level troughs frequently combine to produce fast-forming thunderstorms with high rainfall intensity.
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