How do trees reduce extreme heat?

Trees reduce extreme heat through evapotranspiration and shade, mitigating the urban heat island effect and protecting vulnerable populations from climate-driven temperature increases.

• Trees mitigate extreme heat through two primary mechanisms: evapotranspiration, where water evaporating from leaves during photosynthesis cools the air and reduces humidity, and the provision of shade.
• In urban environments, building materials like concrete reflect heat, creating the 'urban heat island effect' where city temperatures are significantly higher than surrounding areas. Increasing tree cover to over 40% of a city block can reduce temperatures by up to 9°F.
• Climate change is increasing the frequency and severity of extreme heat, which disproportionately affects vulnerable groups such as those without air conditioning or outdoor workers, the latter of whom have seen a fourfold increase in days spent in hazardous heat conditions.
• Beyond heat reduction, forests provide additional climate resilience by buffering the impacts of floods through soil anchoring and the prevention of erosion.

APA

WWF International (n.d.). How do trees reduce extreme heat? https://www.worldwildlife.org/resources/explainers/how-can-trees-reduce-extreme-heat/

Chicago

WWF International. How do trees reduce extreme heat? n.d. https://www.worldwildlife.org/resources/explainers/how-can-trees-reduce-extreme-heat/.

Wikipedia

{{cite report |author=WWF International |title=How do trees reduce extreme heat? |url=https://www.worldwildlife.org/resources/explainers/how-can-trees-reduce-extreme-heat/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{wwfinternationalndhow, author = {{WWF International}}, title = {{How do trees reduce extreme heat?}}, institution = {WWF International}, url = {https://www.worldwildlife.org/resources/explainers/how-can-trees-reduce-extreme-heat/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }