RKI estimates 15 800 heat-related deaths, Germany records second-warmest summer since 1881

DWD placed the summer mean 3.3°C (5.9°F) above the 1961–1990 reference period and 2°C (3.6°F) above the warmer 1991–2020 reference period. Only summer 2003, with a national mean of 19.7°C (67.5°F), was warmer, exceeding the provisional 2026 mean by 0.1°C (0.2°F).

RKI’s cumulative estimate covers calendar weeks 15–33, from April 6 through August 16, rather than the June–August meteorological summer alone. The institute estimated 15 800 heat-related deaths nationally and said the 2026 estimate remained incomplete when the report was issued on August 27.

People aged 85 and older accounted for an estimated 7 960 deaths, while those aged 75–84 accounted for 3 910. These two age groups represented the largest share of estimated heat-related mortality.

Heat-related mortality is not determined by counting death certificates that list heat as the underlying cause. RKI said heat directly causes death in some cases, including heatstroke, but most heat-related deaths involve a combination of heat exposure and existing medical conditions.

RKI calculates the estimate from the difference between modeled deaths with and without heat. To model mortality without heat, the temperature input is capped at approximately 20°C (68°F).

RKI’s model attributed approximately 9 600 of the estimated heat-related deaths to the exceptionally hot calendar week 26 in late June and about 4 000 to calendar weeks 31–33 from late July through mid-August.

The institute separately estimated excess mortality of 20 500 deaths during calendar weeks 20–33, with a 95% prediction interval of 16 100–24 600. Excess mortality measures deaths above the number normally expected, while estimated heat-related mortality isolates the modeled effect of heat, meaning the two figures are not interchangeable.

DWD calculated a national average of approximately 22 hot days with maximum temperatures of at least 30°C (86°F) and five very hot days reaching at least 35°C (95°F). The agency described that frequency as unprecedented in its provisional summer assessment.

Möckern-Drewitz in Saxony-Anhalt reached 41.8°C (107.2°F) on June 27, setting a provisional national temperature record. During the following night, the temperature at Kubschütz in Saxony did not fall below 29.4°C (84.9°F), the highest nighttime minimum recorded in Germany.

DWD provisionally calculated approximately 171 mm (6.73 inches) of precipitation nationwide, equivalent to about 72% of the 1961–1990 seasonal reference of 239 mm (9.41 inches). The provisional sunshine total reached approximately 779 hours, placing summer 2026 among Germany’s five sunniest summers since the series began in 1951.

DWD said all figures remained provisional because not all measurements from its station network were available before publication. Data used for the final day of the meteorological summer were partly based on forecasts, while precipitation and sunshine totals may change following additional submissions and quality checks.

Before 2026, the highest RKI estimates in its 2016–2025 comparison occurred in 2018 and 2019, with approximately 7 000 or more heat-related deaths in each year. The interim 2026 estimate was already well above those earlier values.

Reference:

¹ Summer Weather in Germany 2026 – DWD – August 31, 2026

² Weekly Report on Heat-Related Mortality, Calendar Week 33 – RKI – August 27, 2026