Overview
- The KNMI main station in De Bilt registered 24.5°C on September 30, breaking the previous record from 1975 and marking one of several warm‑record days in 2026.
- Other observing sites reported even higher local highs, including 27.1°C at Hupsel and 28.5°C at Twente Airport, showing large local variation in the late‑September heat.
- Nights were unusually mild in the heat spell, with places such as Eindhoven not falling below 18°C overnight, a condition meteorologists described as exceptional for the time of year.
- Forecasters say the episode was caused by warm air advection from Southeast Europe under a high‑pressure ridge and that the coming weekend will remain mild and mostly dry before a likely shift to cooler, more unsettled weather around mid‑next week.
- Observers report limited immediate stress on wildlife but warn that repeated warm, dry tendencies could accelerate drought, strain water supplies and raise management challenges for nature and agriculture; long‑term data show the Netherlands has warmed about 2.5°C since the start of instrumental records.