Amsterdam urges curtains outside as heatwave tops 37 degrees celsius
Amsterdam officials are urging residents to hang curtains, bedsheets, or blankets outside their windows as a severe June heatwave pushes temperatures past 37 degrees celsius across the Netherlands. With Dutch homes built for damp winters and oversized glass, blocking sunlight before it hits the pane is now a public-health priority, not a décor choice.
Key Takeaways
- Amsterdam's heat coordinator went viral urging exterior curtains to stop solar rays reaching large windows.
- KNMI extended its Code Red heat warning into Saturday as southern temperatures topped 37 degrees celsius.
- Experts say shading glass from outside cuts heat transfer more effectively than relying on indoor blinds alone.
- Cities are also testing mobile jungle blocks, pergolas, and shadow art to cool streets.
- Amsterdam records roughly 110 heat-related deaths yearly; officials warn that figure could reach 600 without stronger adaptation.
Why is Amsterdam asking people to hang curtains outside?
In a viral social media post, Eline Coolen, heat coordinator at the city's public health institute, told residents to rig temporary curtain rails or drape fabric outside. The goal is to intercept sunlight before it reaches the glass.
Coolen drew inspiration from sheets already hanging in Amsterdam-Noord and from balcony blinds she saw in Barcelona. "In Dutch houses, but also in many houses in northern Europe, you have very big windows," she told The Guardian. "We have always built for the winter, when you want as much sun and warmth in your house as possible."
How hot is the Netherlands heatwave?
The KNMI weather bureau extended its Code Red warning into Saturday for Limburg, Brabant, Gelderland, and Overijssel as the heatwave persisted, DutchNews.nl reported. Temperatures topped 37 degrees celsius in the south on Friday, while much of the country saw readings above 30 degrees celsius except on some Wadden Sea islands.
The crisis disrupted daily life. Saturday's military parade for Veterans' Day was cancelled, along with several festivals and concerts. Hospital emergency departments reported more patients with heat-related complaints, including worse asthma and COPD symptoms, heart issues, and dehydration among elderly people and children.
Do exterior curtains actually keep homes cooler?
Mechanical engineering professor Bert Blocken told The Guardian that research consistently shows the best way to keep buildings cool is to keep out the sun, ideally without energy-intensive air conditioning. Blocking rays before they heat the glass reduces indoor heat transfer.
A Vereniging Eigen Huis survey cited by Yahoo found 23% of respondents said their homes still became too hot during heatwaves despite cooling efforts. Sandra Phlippen of ABN Amro noted that one night of sleep loss during extreme heat can cost close to €200 in productivity.
What else is the Netherlands doing to beat the heat?
The government activated its national heatwave plan, focusing on elderly and vulnerable residents. RIVM, the national public health institute, frames responses across behaviour, housing, and urban design. Werner Hagens, who coordinates the heatwave plan, said awareness campaigns appear to reduce deaths during extreme heat.
Researchers are trialling fake trees, pergolas draped in greenery, mobile jungle blocks, and shadow art to shade pavements and pedestrians. Jeroen Kluck, a climate-resilient cities professor at Amsterdam University of Applied Sciences, said creating shade with drought-tolerant plants helps make cities more liveable on hot days. For more on how cities are rethinking built environments under climate pressure, see our Future Tech & AI Wonders coverage.
Construction firms including Dura Vermeer, BAM, and Structon halted non-essential outdoor work. Coolen warned that without stronger measures, Amsterdam's annual heat death toll of 110 could climb toward 600 in future summers.