Higher soil moisture enhances temperature buffering in temperate broadleaf forests by improving canopy shading and increasing evapotranspiration. This study analyzed 54 sites in Central Europe over four summers, finding that forest understories were on average 2°C cooler than outside. Soil moisture significantly influenced temperature offsets, with higher moisture leading to greater cooling. The effect was more pronounced on drier soils and sun-exposed slopes. As climate change increases droughts, the buffering capacity of forests may decline, threatening understory biodiversity. The study highlights the need to incorporate soil moisture into models predicting forest microclimate, biodiversity, and tree regeneration. Future research should focus on developing models that account for dynamic soil moisture and temperature interactions, especially in complex landscapes. Forest management should prioritize maintaining soil moisture to support understory species and mitigate climate impacts.Higher soil moisture enhances temperature buffering in temperate broadleaf forests by improving canopy shading and increasing evapotranspiration. This study analyzed 54 sites in Central Europe over four summers, finding that forest understories were on average 2°C cooler than outside. Soil moisture significantly influenced temperature offsets, with higher moisture leading to greater cooling. The effect was more pronounced on drier soils and sun-exposed slopes. As climate change increases droughts, the buffering capacity of forests may decline, threatening understory biodiversity. The study highlights the need to incorporate soil moisture into models predicting forest microclimate, biodiversity, and tree regeneration. Future research should focus on developing models that account for dynamic soil moisture and temperature interactions, especially in complex landscapes. Forest management should prioritize maintaining soil moisture to support understory species and mitigate climate impacts.