The first heatwave begins with 77% of municipalities at health risk levels.

Spain is experiencing its first heatwave of the summer starting this Saturday. This is an early episode: only 11 of the 75 heatwaves recorded by the State Meteorological Agency (Aemet) since 1975 in the Peninsula began in June.

The forecast from this agency indicates that the peak days of the heatwave will be Sunday the 29th and, with some uncertainty, Monday the 30th, when maximum temperatures will exceed 40 degrees Celsius in many areas of the Peninsula.

These extreme heat events have a direct impact on health, worsening diseases and even increasing mortality. The heatwave begins with 77% of municipalities in the country under some active health risk warning.

Specifically, this Saturday there are 1,136 municipalities in high-risk areas for health due to heat (13%), 2,174 in medium risk (27%), and 3,037 in low risk (37%). Check the map for areas where heat will reach dangerous levels for health, according to the data from the Ministry of Health and Aemet.

This heatwave is expected to last at least until Wednesday, July 2nd. “Although it is likely that in the center and south of the peninsula, and perhaps also in the northeast, high temperatures will persist for several more days,” says Rubén del Campo, Aemet spokesperson. It will affect a significant part of the Balearic Islands and the Peninsula, especially the southwestern quadrant, the Ebro Valley, and the northeastern depressions.

There is no single definition of what constitutes a heatwave. For Aemet, which has issued the alert in Spain, it is an episode lasting at least three consecutive days in which at least 10% of weather stations record maximum temperatures above the 95th percentile of their historical daily maximums for the months of July and August between 1971 and 2000.

Since 1975, Aemet has recorded 75 heatwaves in the Iberian Peninsula and 57 in the Canary Islands. Climate change caused by greenhouse gas emissions from humans has made these events more frequent and intense in Spain. Moreover, they are also starting earlier: between 2024 and 2000, nine heatwaves beginning in June were recorded in the Iberian Peninsula, while between 2000 and 1975 Aemet recorded only two.

Although no heatwave warning was declared until this Saturday, it does not mean that it has not been hot. In fact, temperatures have been above normal, and Aemet forecasts that this month will be the hottest June since its records began in 1965. “June will end as the hottest in the historical series, surpassing those of 2003 and 2017, which were tied for first place,” emphasized the Aemet spokesperson on Friday.

Since late May, many days have recorded typically summer-like average temperatures. This has led to increased health risk alerts due to high temperatures, activated by the Ministry of Health. In fact, every day so far in June, except for three, there have been active warnings of this type in Spain.

Health Risks

Heat has direct impacts on public health and increases mortality. A team from the Carlos III Health Institute has calculated the maximum temperatures at which statistically significant increases in deaths occur in so-called meteosalud areas (territorial areas composed of several municipalities that are homogeneous in terms of daily temperature behavior). This study provides the basis for launching health alerts, which are supplemental to those issued by Aemet (which are based solely on temperature).

The health alert system divides Spain into 182 meteosalud zones with a maximum temperature threshold established based on recorded mortality in each region when extreme temperatures are reached. To determine the alert levels for each day, a 72-hour window is considered, given the impact of persistent heat on health.

Tomorrow there will be [[high_risk_areas]] meteosalud zones at level 3 and [[medium_risk_areas]] at level 2 in Spain. The temperature in the coming days.

Evolution of the Heatwave

This Saturday, temperatures are expected to exceed 38 degrees Celsius generally in the southwestern quadrant and locally in the northern plateau, eastern southern plateau, and the valleys of the Júcar and Segura. It is predicted that temperatures will reach between 40 and 42 degrees in the valleys of the Guadalquivir, Genil, Guadiana, Tajo, and Ebro, as well as in the northeastern depressions.

Aemet considers that the peak days of the heatwave will be Sunday the 29th and, with some uncertainty, Monday the 30th, when values above 40 degrees will extend across both the southwestern quadrant and the middle Ebro valley, potentially reaching locally in the Miño valley. “Temperatures are expected to exceed 42 in the Guadalquivir, Guadiana, and Tajo areas, not excluding the Ebro,” states the special warning issued by this state agency. “High temperatures are also expected in the northern plateau, interior of Mallorca, and in the Júcar and Segura valleys, where temperatures will reach 36 ºC and occasionally 38 ºC.” Additionally, on Monday, it will also be warm in the eastern Cantabrian region, it adds.

This episode will also be characterized by high minimum temperatures (not dropping below 23 or 25 degrees in many areas of the southern half and the Ebro valley), which will lead to sultry nights. The Canary Islands will also experience significant heat, with temperatures reaching between 30 and 36 degrees in the coming days, but not exceeding the thresholds for a heatwave declaration.

In the table, you can check Aemet’s forecast in your municipality and whether it is expected to exceed the risk threshold for the meteosalud area where you are located.

Regions on Alert According to Aemet

In addition to health alerts and heatwave warnings, there is a Meteoalert plan from Aemet. This plan includes the declaration of alerts related to high temperatures. The following map shows the areas that have active warnings for maximum temperatures.

In this case, alerts are established according to specific thresholds for each area on a specific day, without the three-day timeframe used by the Ministry of Health’s map, and without considering mortality. For example, in the metropolitan area of Madrid and Henares, the yellow alert is activated from 34 degrees and the red alert when it exceeds 42 degrees, while in the Canary Islands or Asturias, the yellow alert is activated at the same temperature, but they reach maximum alert at 40. To calculate these thresholds, Aemet relies on historical temperature data from each area.

How to Protect Yourself Against Extreme Temperatures

Heat has direct impacts on public health, especially among children and the elderly or those with chronic illnesses. In the context of increasingly prolonged and frequent heatwaves, it is crucial to prevent the effects of excessive temperatures.

Hydrate

Drink liquids even if you are not thirsty. Avoid alcohol, caffeine, and very sugary drinks.

Have light meals that help replenish salts without overloading your body.

Protect

Be cautious with at-risk groups and individuals with illnesses that may worsen with heat.

Limit exposure, use sunscreen, and wear light, loose clothing, preferably in light colors.

Do not leave anyone in closed vehicles, even for short periods.

Cool Down

Stay in cool places with adequate ventilation or air conditioning whenever possible.

Reduce physical activity during the hottest hours of the day to avoid heatstroke.

What Comes After This Heatwave?

The heatwave is expected to last at least until Wednesday the 2nd. Afterward, temperatures will moderate somewhat. And what follows? More heat above normal. That is the forecast Aemet has for the weeks from July 6 to 20. “It is most likely that a fully summery time will continue, with high temperatures (higher than normal values in most of the Peninsula and the Balearic Islands and closer to their normal average in the Canary Islands),” states the agency in a statement, in which it advises caution with long-term forecasts like this because they may change.