Climate Shift Index Alert•June 18, 2025
Climate change is fueling early-season heat scorching Spain
Intense heat, currently gripping much of Spain and parts of southern France, will last through June 21. Temperatures could potentially reach up to 40°C in some areas, well above normal for mid-June. Climate Central analysis shows that human-caused climate change has made this extreme heat at least five times more likely across nearly all of Spain.
Note: This event may continue beyond June 21. Use the Global Climate Shift Index map to stay updated on heat in your region.
How unusual is the forecasted heat?
Over this five-day stretch, forecast temperatures across much of Spain are expected to run 6°C to 8°C (11°F to 14°F) above the 1991-2020 average.
Daytime highs are forecast to exceed 35°C (95°F) across large parts of the Spanish mainland, including Navarra, La Rioja, and Aragón. Some areas in southern France could approach 40°C (104°F).
Spain’s national meteorological agency (AEMET) has issued multiple orange-level heat alerts from Tuesday, June 17, through the weekend.
Overnight temperatures are forecast to remain 6°C to 8°C above normal, with lows in the 22°C to 24°C (72°F to 75°F) range — particularly along the Mediterranean coast and in central and southern Spain.
An upper-level low positioned near the Azores is amplifying a blocking high over Spain and parts of Europe, trapping a warm plume of air from northwest Africa over the region.
How has climate change influenced this heat?
Daily average temperatures are expected to reach Climate Shift Index (CSI) levels of 5 across nearly all of Spain this week. A CSI level 5 indicates that human-caused climate change made this excessive heat at least 5 times more likely, signifying an exceptional climate change event.
Over the entire period, 45.2 million people across the country – around 94% of the total population – will experience at least one day with CSI level 5.
City | Date of the highest temperature (from June 17 to 21) | Highest temperature (°C) | Departure from normal that day (°C) |
|---|---|---|---|
Mérida | June 20 | 39.8 | 8.2 |
Sevilla | June 20 | 40.5 | 7.6 |
Valladolid | June 21 | 34.7 | 7.1 |
Madrid | June 19 | 36.6 | 6.9 |
Zaragoza | June 21 | 38.0 | 6.4 |
Girona | June 21 | 32.2 | 5.8 |
Murcia | June 17 | 35.3 | 5.1 |
Valencia | June 21 | 32.5 | 4.3 |
What do experts say?
Dr. Zachary Labe, Climate Scientist at Climate Central, said:
“With each passing summer, the odds of dangerous and long-lasting heat waves are growing. A Climate Shift Index level of 5 indicates that this extreme heat was made exceptionally likely by climate change. Events like this pose serious risks to public health, ecosystems, food systems, safety, and the reliability of infrastructure.”
To request an interview with a Climate Central scientist, please contact Abbie Veitch at aveitch@climatecentral.org.
How do we know climate change is influencing this heat?
The Climate Shift Index uses peer-reviewed methodology and real-time data to estimate how climate change has increased the likelihood of a particular daily temperature.