June 29, 2026 becomes the deadliest summer day in Czechia in 30 years

On June 28, 2026, Czechia experienced an all-time temperature record: in Doksany in the Polabí region, the thermometer hit a historic 41.9 degrees Celsius, while the average daily temperature reached 28.3 degrees — 11 degrees above the long-term norm. The following day, June 29, the heat eased slightly, but tropical conditions persisted — and this particular day turned out to be the deadliest of the entire summer, and according to preliminary data from the Czech Statistical Office obtained by Seznam Zprávy, the harshest summer day the country has seen in more than three decades.

That day, 425 people died in Czechia — more than on any other day so far this year, including the winter months, when mortality is typically higher due to infections and the strain cold puts on the body.

Similar figures were last seen in 1994

“Such a rise in mortality in summer is unusual, and given that Czechia — along with much of the region — was gripped by extreme heat at the time, a link to the record temperatures is highly likely,” said Terezie Štiglerová, head of the demographic statistics department at the Czech Statistical Office.

According to her, a more precise connection can only be established once cause-of-death statistics are published — that will show whether deaths from cardiovascular and respiratory illnesses, which tend to worsen in extreme heat, actually rose. However, such data is only released once a year, with a delay of several months. For now, daily mortality figures are available only up to June 30, so a full assessment of the heatwave’s impact is premature — and the preliminary numbers may still be revised.

Štiglerová noted that even during severe heatwaves in 2015 and 2018, statisticians never recorded more than 400 deaths in a single day. Such daily death tolls in the summer months were last seen in Czechia in 1994, and on isolated days in the early 1990s and late 1980s. “Back then, however, overall mortality conditions in the country were quite different — the total number of deaths was generally higher, and life expectancy was seven to eight years lower,” she added. It’s impossible to look further back in history, since daily statistics have only been recorded since 1986.

An anomaly across Europe

Weekly statistics had already pointed to unusually high mortality during the heatwave spanning late June and early July. In week 27 of the year, from June 29 to July 5, a total of 2,299 people died in Czechia — 350 more than the average for the same period over the previous five years.

According to Pavel Zahradníček, an expert with the InterSucho portal and a researcher at the Global Change Research Institute of the Czech Academy of Sciences, excess mortality during heatwaves is a common occurrence, though rarely on this scale. He also points out that there’s no established pattern of mortality peaking the day after the temperature maximum, as happened this year.

Older people are at the greatest risk during heatwaves, along with patients suffering from heart and kidney conditions or low blood pressure. Heavy sweating causes the body to lose water and minerals. “Dehydration causes blood pressure to drop, and if a person is also taking medication to lower blood pressure, the combined effect can be too strong,” explained Aleš Linhart, a physician at Prague’s General University Hospital. Weakness, headaches, and dizziness can occur even in otherwise healthy people.

Other European countries have also confirmed excess mortality linked to the record heat. According to incomplete data, at least 35,000 people may have died across the continent as a result of the heatwave. Germany reports roughly 15,800 excess deaths above the long-term average, 9,600 of them in the single week from June 22 to 28 alone, according to the Robert Koch Institute. In Spain, around 4,500 heat-related deaths were recorded between June 1 and August 19, while France logged approximately 7,000 excess deaths in June and July.

Source: seznamzpravy.cz