Abstract Researchers are increasingly examining discourses associated with climate change and extreme weather events across different communication channels. However, further research is needed to examine how environmental non-governmental organizations (NGOs) frame extreme weather events and their relationship to climate change on social media platforms. This is an important topic as these groups play a significant role communicating science and driving environmental action. Here, we examine how Australian climate action NGOs framed the relationship of the 2019–2020 Black Summer bushfires to climate change on Twitter/X. Analyzing 2,077 bushfire-related tweets from a sample of 102 climate group accounts through manual content analysis, we found that these groups frequently linked bushfires with climate change, representing 59% of their bushfire-related tweets during the period of the fires. Forty-two percent of tweets mentioned climate change without describing how it relates to bushfires; 16% described specifically how climate change influences the frequency and intensity of bushfires; and only 1% suggested inaccurately that climate change causes bushfires to occur. Fifteen percent of tweets discussed risk factors beyond climate change that influence bushfire impacts, such as firefighting, emergency responses, hazard reduction, and community vulnerabilities. Only seven accounts mentioned an extreme event attribution study of the Black Summer fires. Based on these findings, we discuss opportunities and challenges of climate science communication in the extreme weather context, and describe promising directions for future research.