Spain issues red alert for Valencia and Zaragoza as temperatures set to exceed 42 °C on Wednesday

Spain's State Meteorological Agency (Aemet) has declared a red alert for extreme heat across three zones on Wednesday: the northern coast and southern coast of Valencia province, and the Ribera del Ebro area of Zaragoza province. Forecasts put maximum temperatures above 42 °C, concentrated between 13:00 and 20:00, with the eastern half of the peninsula and the Balearic Islands also facing significantly elevated readings.

The episode coincides with the start of the canícula, the period traditionally considered the hottest of the year, running from 15 July to 15 August. A potent ridge of dry, very warm African air laden with suspended dust is driving temperatures upward, bringing calima that will reduce visibility and degrade air quality.

Where the red warnings apply

Aemet has placed the northern coast and southern coast of Valencia province under a red warning for extraordinary danger. In Zaragoza, the Ribera del Ebro is at the same top-tier alert level. The interior north of Valencia province is also named among the red-alert zones by the agency, meaning three distinct areas face the highest risk classification.

Orange warnings for important danger cover the interior of Valencia province, the whole of Alicante province, inland southern Castellón, Catalonia, the rest of Aragón, Castilla-La Mancha, Andalusia, the Region of Murcia and the Balearic Islands, where maxima are forecast to range between 38 and 41 °C. Yellow warnings are in effect for Madrid, Navarre, La Rioja and the remainder of Castellón province, with temperatures between 34 and 38 °C.

The Wednesday 15th will see temperatures exceed 42 °C in the zones of the northern coast and southern coast of Valencia province and in the Ribera del Ebro in Zaragoza. Extraordinary danger! Follow Civil Protection recommendations.

What makes Wednesday's heat dangerous

The risk on Wednesday goes beyond air temperature alone. Aemet specialists flag an unstable atmosphere in which late-arriving sea breezes will battle westerly winds over the interior. The convergence may trigger dry thunderstorms that, in a parched air mass, are capable of producing sudden violent wind gusts and warm downbursts, known as reventones cálidos, along the Valencia coast during the evening and night.

Forecasters note that the exact time the sea breeze pushes inland will determine how high temperatures climb at different points. In Valencia city, westerly winds are expected to hold until 15:00, after which the breeze should begin its advance toward the pre-coastal strip. In pre-coastal areas where the breeze penetrates later, readings could exceed 42 °C.

The convergence of easterly breezes with westerly winds in the interior may set off thunderstorms.

Health and fire risk warnings

The regional 112 emergency coordination centre has urged the public to exercise extreme caution, particularly in the evening and overnight hours when reventones are most probable. People are advised to avoid outdoor activity, especially during the central hours of the day, and to pay close attention to the elderly and those with cardiovascular conditions.

Aemet's spokesman Rubén del Campo noted that the effect of heat on health will be compounded by a deterioration in air quality caused by the arrival of suspended dust from North Africa. Forest fire risk across the Valencian Community is rated very high or extreme, with municipalities and emergency services asked to maintain heightened readiness.

To the effects of heat on health we will have to add the worsening air quality produced by the arrival of suspended dust.

Outlook for the rest of the week

Thursday 16 July will bring a slight easing, with Valencia city's maximum falling to around 34 °C and the minimum near 25 °C under intervals of cloud. The temperature drop will bring readings closer to seasonal norms, though heat will remain high across the eastern peninsula.

Friday will be mostly cloudless in the morning, with cloud building toward midday and little change in temperatures, between 23 and 33 °C in Valencia. The weekend will see partly cloudy skies both Saturday and Sunday, with maximums above 31 °C and minimums around 23 to 25 °C. Light easterly breezes will persist.

Further inland, capitals such as Murcia could reach 42 °C on Thursday and 43 °C on Friday. By Sunday, Badajoz, Ciudad Real and Toledo are forecast to hit 44 °C.