Natural hazards often occur in combination with other natural hazards rather than as isolated events. While some combinations of hazards are well studied and their physical connection is increasingly understood, other combinations have received considerably less attention. High temperatures are known to be an important component for conditions that lead to heavy rainfall; however, sequences of heatwaves followed by heavy rainfall are not well understood, especially in a compound event context. Here, we analyse heatwave–heavy rainfall events across Australia using rainfall observations at hourly resolution. Our results show that heavy rainfall is more likely to occur if preceded by a heatwave, demonstrating that heatwave–heavy rainfall sequences should be seen as temporally compounding events. In particular, many regions in Australia experience both more frequent and more extreme wet days immediately following a heatwave. This behaviour is strongest in coastal regions, especially on the Australian east coast. These findings highlight the need for heatwave–heavy rainfall sequences to be studied as compounding events, as future changes in either hazard is likely to have impacts on related risks such as flash flooding.

中文翻译：

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澳大利亚暂时复合的热浪-强降雨事件

自然灾害通常与其他自然灾害一起发生，而不是作为孤立事件发生。虽然一些危害的组合得到了很好的研究，并且它们的物理联系也越来越多地被理解，但其他组合受到的关注却少得多。众所周知，高温是导致强降雨条件的重要组成部分；然而，人们对热浪之后暴雨的顺序还不是很了解，尤其是在复合事件背景下。在这里，我们使用每小时分辨率的降雨观测来分析澳大利亚各地的热浪强降雨事件。我们的结果表明，如果在热浪之前发生强降雨，则更有可能发生强降雨，这表明热浪-强降雨序列应被视为时间上的复合事件。尤其，澳大利亚的许多地区在热浪过后立即经历更频繁和更极端的潮湿天气。这种行为在沿海地区最为强烈，尤其是在澳大利亚东海岸。这些发现强调了将热浪-强降雨序列作为复合事件进行研究的必要性，因为这两种灾害的未来变化都可能对山洪暴发等相关风险产生影响。