Can first-hand experience of a climate-related natural disaster make citizens more likely to vote in favour of progressive climate politics? Leveraging the rare occurrence of a large-scale disaster just two months before a federal election, we use a difference-in-differences design to study the short-term electoral effects of the devastating 2021 Germany floods on voter support for Germany’s major environmentalist party, the Green Party. Compared to other German voters, those living in areas affected by the floods were marginally (0.4–1.6 percentage points) more likely to vote for the Greens. The largest increases in Green vote share are observed in municipalities which were directly exposed to flooding. Contrary to expectation, we tend to find larger increases in Green Party support in the less severely affected areas. Despite substantial increases in turnout in affected areas, we find that the observed increase in vote share for the Greens was rather driven by a persuasion effect on voters who previously supported other parties. In the absence of evidence that the floods led to an increase in voters’ issue prioritisation of climate change, our results highlight the limited possibility for major natural disasters to induce increased localised support for Green parties.