WWA: Record-breaking heatwave triggers 17-fold increase in Greenland ice melting

Unseasonably high temperatures struck Iceland and Greenland in mid-May, with weather stations across both countries recording extreme heat far above seasonal norms.

The melting of the Greenland ice sheet from May 15-21 was about 17 times higher than average for this period, Caliber.Az reports, citing World Weather Attribution.

On May 15, Egilsstaðir Airport in eastern Iceland registered a scorching 26.6°C, setting a new national record for the highest temperature ever recorded in May, according to the Icelandic Met Office (2025). Across the country, temperatures soared to more than 10°C above the monthly average.

Meanwhile, on May 19, the remote Ittoqqortoormiit station on Greenland’s eastern coast recorded 14.3°C—over 13°C higher than the typical May daily maximum of 0.8°C, according to the Danish Meteorological Institute (DMI, 2025).

Meteorologists attribute the extreme warmth to a persistent atmospheric setup: a high-pressure system parked near the Faroe Islands and a low-pressure system situated south of Cape Farewell created a sustained southerly airflow that funneled warm air into the region. This unusual pattern remained in place for about nine days, triggering a rare and early-season heatwave. Although similar configurations have been seen in the past, experts note that this episode stood out for both its early timing and duration.

While immediate impacts have been limited, scientists warn of potential longer-term consequences. Arctic and sub-Arctic ecosystems, finely tuned to cold climates, are particularly vulnerable to early-season warming. Even brief periods of abnormal heat can disrupt local flora and fauna, with ripple effects on communities that rely on these fragile systems for sustenance and livelihoods.

The heatwave also underscored stark differences in how communities across the Arctic experience warming. While Iceland’s modern infrastructure allows for better adaptation, Greenland—particularly its remote settlements—faces far greater challenges. During a similar episode of extreme heat and rainfall in 2022, permafrost melt released iron and other metals into Arctic lakes, prompting widespread concern over water contamination.

Sanitation remains another critical issue. While urban areas in Greenland are equipped with piped sewage systems, around 90% of rural homes still rely on bag toilets, which are disposed of in open areas. Rising temperatures raise health risks, as warmer conditions accelerate bacterial growth and increase the likelihood of disease transmission.

To better understand the role of human-induced climate change in driving these extremes, a team of researchers from Iceland, the Netherlands, Sweden, Denmark, the United States, and the United Kingdom conducted a rapid attribution study. The analysis focused on the seven hottest days in May across Iceland—where the heat persisted the longest and affected the largest number of people—as well as on the single hottest May day at Egilsstaðir Airport, Reykjavik, and Ittoqqortoormiit. The study aims to determine the extent to which climate change intensified the heatwave and increased its likelihood.

By Khagan Isayev