A fleeting period of unseasonably warm weather, often termed an Indian Summer, is expected to bring pleasant conditions to parts of Europe, including the Netherlands, from September 18th to 21st, 2025. This warm interlude follows a week of unsettled and cooler weather, offering a temporary embrace of autumnal sunshine.
In Amsterdam, temperatures are forecast to rise significantly. Friday, September 19th, is projected to reach a high of 26°C (78°F) under clear, sunny skies. This warmth is expected to continue into Saturday, September 20th, with a high of 25°C (77°F), though increased cloud cover may temper the day later on. However, this pleasant spell is predicted to be short-lived. By Sunday, September 21st, a return to cooler weather is anticipated, bringing with it the possibility of rain and thunderstorms, with maximum temperatures expected to drop to around 18°C (64°F).
The phenomenon known as Indian Summer, characterized by a spell of warm, calm, and often hazy weather in autumn, typically occurs between September and November in temperate Northern Hemisphere regions. In Europe, this period is sometimes locally known as "Altweibersommer," a term with various etymological interpretations, including a reference to spider webs or the gentle, lingering warmth of the season. Scientifically, these warm spells can be linked to the influence of large high-pressure systems, such as the Azores anticyclone, which can transport stable, warmer air masses from the south.
This anticipated warm spell arrives after a notably challenging summer for the continent. Europe experienced its hottest summer on record in 2024, marked by intense heatwaves and severe droughts that significantly impacted agriculture. For instance, Austria estimated agricultural losses of up to 150 million euros due to drought in 2024. Such extreme weather events highlight the delicate balance of our climate and its profound influence on daily life and economic stability, underscoring the importance of understanding and adapting to these climatic shifts.