Lorraine Williamson
Spain is preparing for its fourth heatwave of the summer, with temperatures expected to climb sharply from Wednesday and remain dangerously high until at least Sunday.
AEMET has placed the probability of the episode at 70%, warning that the most intense heat will affect the south-west, the Ebro Valley, north-eastern depressions, parts of the Pyrenees and the Canary Islands. Night-time temperatures will also remain unusually high in many areas, limiting relief from the heat. AEMET’s latest special warning says conditions may continue into next week.
Temperatures could reach 42°C
The heatwave is expected to begin on Wednesday, 29 July, as temperatures rise significantly across eastern Spain.
AEMET forecasts highs of between 39°C and 41°C in the main river valleys of the south-west, while temperatures of 40°C to 42°C are possible in the Ebro Valley and north-eastern depressions. Parts of the northern plateau and La Mancha could reach between 37°C and 39°C.
The heat is expected to intensify further by Friday, when inland areas of southern Spain could also reach 40°C to 42°C. Temperatures are likely to remain at similar levels throughout the weekend, although the precise forecast becomes less certain several days ahead.
In the Canary Islands, temperatures may exceed 37°C in inland and elevated areas of Gran Canaria, Tenerife, La Palma and Fuerteventura. Calima is also expected above the islands’ remaining layer of cooler, more humid air.
Warm nights will increase the health risk
The danger will not be limited to the afternoon.
AEMET expects very warm nights in several regions, particularly in areas where temperatures remain high for consecutive days. When buildings and streets cannot cool overnight, the strain on the body increases, and people have less opportunity to recover before the heat builds again.
The greatest danger is for older people, young children, those with cardiovascular or respiratory conditions, pregnant women and people who work or exercise outdoors. Anyone living alone or without access to effective cooling may also be particularly vulnerable.
Spain’s Ministry of Health has warned that the health risk rises once local temperature thresholds are exceeded for several consecutive days. These thresholds differ by area because the effect of heat depends not only on the temperature itself but also on local climate and how accustomed the population is to extreme conditions. The national heat-health plan divides Spain into 182 monitoring areas with locally adjusted risk levels.
Wildfire danger could become extreme
The latest heatwave arrives while emergency crews are still dealing with the aftermath of major fires in Ávila, Madrid, Toledo and Castellón.
Civil Protection says the wildfire danger will continue to increase and may reach extreme levels as high temperatures combine with low humidity and locally strong southerly winds. The conditions could make it harder to secure existing fire perimeters and increase the chance of new outbreaks. Officials have warned that the heat may complicate firefighting operations throughout the second half of the week.
Even where a fire has been contained, buried roots, tree stumps and pockets of vegetation can remain hot for days. Strong winds may then carry embers beyond control lines or cause apparently extinguished areas to reignite.
Authorities are urging the public to avoid machinery, barbecues, discarded cigarettes or any outdoor activity that could produce sparks. Smoke or flames should be reported immediately through the 112 emergency number.
Heat has already had a serious health impact
The approaching heatwave follows an unusually severe start to the hot-weather season.
Spain’s daily mortality-monitoring system estimated 101 deaths attributable to high temperatures during May 2026, the highest total recorded for that month since the series began in 2015. The figure was more than three and a half times the May average for the previous decade.
Health officials estimate that 27,564 deaths were attributable to high temperatures between 2015 and 2025. The risk of mortality increases by between 9.1% and 10.7% for every degree by which temperatures rise above the local health threshold. The Health Ministry says the figures demonstrate that dangerous heat can have an impact well before the traditional height of summer.
These are statistical estimates based on excess mortality and temperature patterns. They do not mean that every death certificate listed heat as the sole or direct cause.
Advice for residents and visitors
People in affected areas should avoid unnecessary exposure during the middle of the day, particularly between approximately 12 noon and 6.00 pm.
Drink water regularly, even before feeling thirsty, and limit alcohol and heavily caffeinated drinks. Wear loose, light-coloured clothing, use a hat and remain in shaded or air-conditioned spaces where possible.
Homes should be ventilated during the coolest hours, and shutters or curtains should be closed when direct sunlight reaches windows. Fans can help, but they may be less effective when indoor temperatures become extremely high.
Never leave children, older people or animals inside a parked vehicle, even for a short time. Anyone experiencing confusion, fainting, very hot skin, severe headache or loss of consciousness may require urgent medical assistance.
Check local warnings before travelling
The heatwave will not affect every part of Spain equally, and warning levels may change as the event develops.
Travellers should check the AEMET forecast for their destination rather than relying only on national temperature maps. Mountain areas, inland valleys and islands can experience conditions that differ sharply from nearby coastal resorts.
Outdoor activities, sightseeing and long road journeys may need to be moved to the early morning or evening. Drivers should carry water, avoid leaving vehicles low on fuel and be prepared for road restrictions near active wildfire zones.
AEMET is expected to update its special warning as new forecast data becomes available.
A prolonged spell of dangerous heat
The episode is currently expected to last until at least Sunday, 2 August, but forecasters say the pattern could continue into the following week.
Its arrival so soon after Spain’s recent wildfire emergency will place renewed pressure on firefighters, health services and communities already dealing with evacuations and damage.
For residents and visitors, the message is straightforward: follow local warnings, reduce exposure during the hottest hours and treat the heat as a genuine health and safety risk.