Although invasive species are recognized as a major threat to freshwaters, little is known about how future climate warming will affect the success of invaders. Ecosystems are also often simultaneously impacted by multiple, potentially interacting, invading species and the management of species invasions can be incredibly difficult. Sensitive methods such as environmental DNA (eDNA) metabarcoding, may be key to the early detection and monitoring of invaders. Therefore, to quantify invader success, we performed an outdoor mesocosm experiment mimicking present and future temperatures (IPCC RPC 8.5) combined with a multispecies invasion of planktonic organisms collected from a region with 3–4°C higher mean temperature. 18S eDNA metabarcoding was used to track invaders and impacts on the established eukaryotic community over 22 weeks. We show that invasion success doubled with climate warming compared to present temperatures, implying a substantial increase in successful establishment of invaders in the future. In addition, after the invasion, species richness increased at warming, but not at present, climate conditions. Our quantification of the establishment of invaders in a climate warming scenario, using advanced eDNA methodologies, provides an important step in understanding and predicting how climate warming may affect the success of invasive species in the future, thereby allowing for more informed management recommendations in adapting society to climate change.