Switzerland Today
Dear Swiss Abroad,
I'm one of those people who jump into cold water. In April, I ventured into chilly Lake Maggiore (13°C) and a fortnight ago I took a dip in the cool waters of Lake Sempach (15°C). However, after a ten-day heatwave in Switzerland, the temperature of Lake Sempach has already risen by a full 8°C – to more than 23°C.
It is not alone. According to the latest data, 24 of Switzerland’s 32 largest lakes are currently experiencing record temperatures for this time of year. Researchers are warning of the consequences for ecosystems, water quality and fish stocks.
Yesterday’s knife attack in Winterthur, in which three people were injured, has shocked Switzerland and triggered a new debate about Islamist radicalisation, mental illness and the role of the authorities.
As emerged on the day of the attack, the alleged perpetrator, a 31-year-old Swiss-Turkish dual national, had been known to security authorities for years as an IS sympathiser. He was released from a psychiatric clinic shortly before the attack. The clinic said it was shocked by the events and immediately launched an external investigation. The Neue Zürcher Zeitung (NZZ) today traces the profile of the man it describes as an “unstable loner”.
Zurich Security Director Mario Fehr described the incident as an “act of terror” and called the release from psychiatric care a decisive “tipping point”, criticising what he saw as a serious misjudgement by doctors. Politicians from several parties are now calling for tougher measures against radicalised offenders, including revoking citizenship and deportation. Swiss law allows dual nationals to be stripped of their citizenship if their actions seriously damage Switzerland’s interests or reputation.
The case has also put the Islamist scene in Winterthur and Switzerland back in the spotlight. According to the Office of the Attorney General, there are currently 140 jihadist-motivated terrorism cases pending in Switzerland – more than ever before.
According to US authorities, Swiss companies allegedly helped the Iranian regime by managing a shadow fleet of oil tankers and processing transactions linked to the financing of the Revolutionary Guards.
An investigation by Swiss public broadcaster SRF’s Rundschau programme examines how Swiss companies are allegedly involved in a network used to circumvent sanctions against Iran. At the centre of the investigation are firms in Geneva, Zug and Zurich accused of facilitating oil shipments, financial transactions and investments for an Iranian business network.
The network centres on Hossein Shamkhani, the son of a close adviser to Iran’s former Supreme Leader, Ali Khamenei. According to US authorities, the network sold Iranian oil to China and India through a so-called shadow fleet. Shamkhani is also accused of supplying the Kremlin with Iranian missiles and drones in exchange for Russian oil. Tankers linked to Geneva-based businessman Mathieu Philippe were allegedly used in the operation. His companies have been on the US sanctions list since 2025.
Another lead points to Zurich-based MBaer Merchant Bank, which is being investigated by the Office of the Attorney General. According to US authorities, more than $60 million (CHF47 million) allegedly passed through the bank in transactions connected to the Iranian Revolutionary Guards. The bank and its founder reject the allegations.
A romantic relationship at Switzerland’s federal court is causing waves: alongside an ongoing investigation into possible conflicts of interest, allegations of covert surveillance have now emerged.
According to media reports, a hidden camera was discovered in a hedge at the Valais home of federal judge Yves Donzallaz. Donzallaz reportedly found the device in early April, several weeks before Weltwoche published revelations about his relationship with fellow judge Beatrice van de Graaf.
Donzallaz filed a criminal complaint and handed the device to police. The Valais public prosecutor confirmed receipt of the complaint. It remains unclear whether images published by Weltwoche could be linked to the camera. Journalist and former Swiss People’s Party parliamentarian Christoph Mörgeli declined to comment on his sources. Donzallaz himself was formerly a member of the right-wing Swiss People’s Party before leaving following a dispute.
Meanwhile, the affair continues to generate political and legal debate. The federal court has commissioned an external investigation. In an interview with CH Media, former federal court president Ulrich Meyer called for resignations and warned of a growing crisis of confidence.
May 2026 is ending warmer than ever before, and temperatures in Swiss lakes are reaching record levels for this time of year. The consequences are not only unpleasant for swimmers but also pose a threat to aquatic life.
Twenty-four of Switzerland’s 32 largest lakes currently have surface temperatures never before recorded at the end of May. They include Lake Zurich, Lake Geneva, Lake Maggiore, Lake Lucerne and Lake Brienz.
Over the past ten days, lake temperatures have risen by an average of almost seven degrees. Lake Zurich currently measures just under 21°C, Lake Geneva 19.4°C and Lake Sempach more than 23°C. Persistent sunshine has rapidly warmed surface waters.
Experts warn of the consequences for swimmers: blue-green algae, bacteria and duck fleas (cercariae) thrive in warmer water. Climate researcher Martine Rebetez describes the warming as a “considerable threat” to fish populations. Trout and char are particularly vulnerable because they depend on cool, oxygen-rich water and struggle when temperatures remain above 20°C for extended periods. Reduced winter mixing of lake waters also lowers oxygen levels at depth, placing additional stress on ecosystems.
Translated using AI/amva/ts
In compliance with the JTI standards
More: SWI swissinfo.ch certified by the Journalism Trust Initiative
