In the French Alps, a new June record was set when the freezing 0C line rose to 5135m above sea level.
The significant early season temperatures are an ominous sign of what’s still to come for the bulk of the hot season - the rise in temperatures and return of high readings are symptoms of human-driven climate change.
Unusually hot summers have been the norm in Europe across recent years: 2024 was the hottest on record, besting 2023, which surpassed the high mark from 2022 and 2021.
A blast of heat
Today is another scorching day on the Iberian Peninsula. Highs in the 40-to-45C range come after several days of records over the weekend.
Spain set a national record on Sunday NZT with 46C. Portugal did so yesterday, logging a high of 46.6C at Mora in the central portion of the country, after first getting there on Sunday with a high of 45.4C in nearby Alvega.
Warm nights, in some cases with temperatures remaining near and above 30C, are also setting widespread records, including as far north as northern Germany.
Heat is being pumped north by a heat dome anchored from North Africa to southern Europe. Large swathes of Morocco and Algeria are under drought, as are other chunks of Europe, which is probably enhancing the high temperatures.
Similar conditions farther south and east were mostly centred on the Mediterranean region late last week as the heat dome expanded northward.
Mountain heat
The persistent warmth of 2025, and in many cases below-average snowfall last winter, has it feeling and looking a lot like late summer despite there being at least two months of the season left.
Over the weekend, a record for June warmth in the French Alps was set when the freezing line rose to 300m above the summit of Mont Blanc, the tallest mountain in the Alps.
It remained at or above freezing for at least a day, according to weather station data near the peak.
“La Meije looks like the end of August after two months of heat,” wrote nature photographer Guillaume Laget, according to a translation of his post on Bluesky. “It’s only the end of June after a few days.”
La Meije soars to about 3960m above sea level.
Human-caused climate change is leading to decreased winter snowfall and increased summer melt.
Glaciers across the continent are rapidly shrinking and disappearing. A study published earlier this year showed that about 39% of ice in Central Europe glaciers has been lost since 2000.
A toasty sea
The heatwave is also cooking the Mediterranean Sea.
While the whole body of water is warmer than normal, the western half is particularly fiery.
Oceanic warmth has led to an expansive marine heatwave, at Level 2 to 3 out of 5, according to Noaa’s Coral Reef Watch.
Warm waters further augment extremes of the air mass by mitigating moderation of heat bubbling up from North Africa.
The higher humidity from warm waters also keeps nearby temperatures from falling as much at night, amplifying risks from lengthy episodes of high temperatures.
Along with the frequent recurrence of significant summertime heat across Europe over recent years, the Mediterranean Sea has also now repeatedly witnessed unusual high temperatures - it set records for maximums in 2023 and again in 2024.
On the current trajectory, 2025 will also vie for that spot.
What’s next?
Heat will remain entrenched through the week in much of Europe.
The hottest temperatures relative to normal - 1 to 15C above average - will shift east over coming days.
A huge chunk of France will face record and near-record temperatures at or above 38C tomorrow as the heatwave peaks there.
Similar temperatures compared to normal also overtake Germany and Italy midweek.
Mid- to late week, the first of several cold fronts should push the hottest conditions southward somewhat, with the highest temperatures stretching from Eastern Europe through the Mediterranean region and to the Iberian Peninsula at the weekend.
