Firefighters battling Spain's worst wildfire crisis on record faced a critical test Saturday as authorities warned that strengthening winds could fuel massive blazes burning west of Madrid, despite cooler overnight conditions that briefly slowed the fires' advance.
The Interior Ministry said winds were expected to reach up to 60 kph (38 mph), raising concerns that the changing weather could undo gains made overnight as emergency crews worked to contain the fast-moving fires.
Two separate wildfires in the Madrid region merged Friday into a single massive blaze. Although the fire has not yet joined another large wildfire burning in neighboring Avila province in the Castilla y Leon region, officials remain concerned that shifting winds could push the fires together.
The fires have already forced more than 35,000 people to evacuate across Madrid and Avila, while tens of thousands more have been ordered to remain indoors because of dangerous smoke and fire conditions. Authorities said more than 30,000 residents were evacuated in the Madrid region alone, with over 20,000 confined to their homes. In Avila, another 5,150 residents have fled while 8,635 remain under stay-at-home orders.
The Madrid regional government said more than 2,000 evacuees are being housed in 14 emergency shelters.
Officials described the overnight weather as a rare opportunity to gain ground against the flames.
"The change in weather conditions, with less wind, higher humidity and lower temperatures, has greatly benefited the fight against the forest fires, which advanced little and decreased in intensity," the central government in Madrid said in a morning update.
Prime Minister Pedro Sanchez visited the fire zone in the village of Cenicientos, where he praised emergency crews while warning that the situation remained unpredictable.
"Our priority is to save lives and protect populated areas," Sanchez told reporters. "We are going to face some complex hours because although temperatures have fallen, we do not yet know how the wind will develop or how strong it will become."
He said the cooler weather had created a "window of opportunity" for firefighters to contain what he described as a very serious emergency before stronger winds returned.
The scale of the disaster has transformed the skies over central Spain. Thick gray smoke blanketed areas west of Madrid, while the smell of burning reached the capital's city center, irritating residents' throats and forcing many to keep windows shut.
In Brunete, one of the affected municipalities, Mayor Mar Nicolas described the destruction as unprecedented.
"Every year there are fires, but this one has been tremendous," she said. "It is a catastrophe."
Authorities have evacuated 10 villages in the Madrid region, while residents in three others have been instructed to remain indoors as crews continue battling the advancing flames.
The Madrid wildfires have burned nearly 10,000 hectares (24,700 acres), while fires in Avila have scorched an estimated 13,000 to 15,000 hectares (32,100 to 37,000 acres). Combined, the blazes have consumed nearly 25,000 hectares (61,800 acres), making them among Spain's largest wildfires in decades.
The fires also disrupted operations at NASA's Deep Space Communications Complex near Madrid, where about 100 employees were evacuated Friday as flames approached the facility.
Interior Minister Fernando Grande-Marlaska said firefighters are also responding to nine other active wildfires across Spain, underscoring the widespread strain on emergency resources.
Spain has already endured an exceptionally destructive wildfire season. Sanchez said roughly 130,000 hectares (321,200 acres) have burned nationwide since January, exceeding the country's average annual burned area over the past decade. Data from the European Forest Fire Information System show more than 168,000 hectares have already burned this year, following Spain's devastating 2025 wildfire season, when more than 393,000 hectares were destroyed.
According to Spanish media, the final two weeks of July have become one of the country's worst periods for large wildfires since records began in 1983, highlighting the increasing intensity of fire seasons driven by prolonged drought, extreme heat and volatile weather conditions.
Spain is racing against time as powerful winds threaten to intensify the country's worst wildfire disaster on record, with nearly 25,000 hectares burned, more than 35,000 people evacuated and firefighters battling to prevent massive blazes west of Madrid from merging into an even larger inferno.