Geneva neighbourhoods face a 4.6-degree heat gap
Tuesday 18th August 2026 on 14:01 in
Switzerland
Geneva’s hottest and coolest neighbourhoods differ by 4.6 degrees, according to an analysis by SRF based on seven public datasets evaluated by French-language broadcaster RTS. The data covers all 129 neighbourhoods in the city and shows that areas with more trees are cooler at night.
The Pâquis district on the lakeshore recorded the highest temperatures during the heatwaves from June to August. Its six neighbourhoods reached 5.6 degrees above the reference temperature, measured over a grassy area at 4am. The Mont-Blanc neighbourhood recorded a difference of 6.2 degrees.
Only 5.6 percent of Pâquis is covered by tree canopies. By contrast, residential neighbourhoods on Geneva’s hills, including Champel-Roseraie and Florissant-Malagnou, have tree canopy coverage of between 25 and 32 percent. Their temperatures were about 3 degrees above the grassy reference area.
The reference measurement reflects the way heat is released in the early morning. Concrete facades, asphalt roads and squares, and flat roofs give off heat stored during the previous day.
Less than 9 percent of the city centre is covered by tree canopies, where the temperature difference from the grassy reference area reaches 5.5 degrees or more. Overall, 62 percent of Geneva’s population, about 127,000 people, live in neighbourhoods with less than 20 percent canopy coverage. About 25,000 people live in areas with less than 5 percent coverage.
The analysis found that every 10 percentage-point increase in tree canopy coverage reduces nighttime heat by 0.8 degrees. It also found no statistical link between high-rise neighbourhoods and higher temperatures. Instead, the amount of sealed ground, including extensive construction, asphalt and gravel, has the greater effect.
Crêts-de-Champel illustrates the distinction. The neighbourhood has the city’s tallest buildings but also 32 percent canopy coverage. Its temperature difference from the grassy reference area is 2.9 degrees, suggesting that building upwards and regulating temperatures are not mutually exclusive.
Raising all neighbourhoods below the 20 percent threshold to that level would require an additional 0.74 square kilometres of tree canopy, equivalent to about 15,000 mature trees. Geneva currently has 42,328 trees.