Heatwaves are an accustomed extreme event of the Australian climate, which can cause catastrophic impacts on human health, agriculture, and urban and natural systems. We have analyzed the trends in Australia‐wide heatwave metrics (frequency, duration, intensity, number, cumulative magnitude, timing, and season duration) across 69 extended summer seasons (i.e., from November‐1951 to March‐2020). Our findings not only emphasize that heatwaves are becoming hotter, longer, and more frequent, but also signify that they are occurring with excess heat, commencing much earlier, and expanding their season over many parts of Australia in recent decades. The Australian heatwave trends have strengthened since last observed Australian study was conducted. We also investigated the heatwave and severe heatwave trends at a local city‐scale using three different observational products (AWAP and SILO gridded datasets and ACORN_SATV2 station data) over selected time periods (1911–2019, 1911–1964, and 1965–2019). Results suggest that heatwave trends are noticeably different amongst the three datasets. However, the results highlight that the severe heatwave cumulative magnitude and their season duration have been increasing significantly in recent decades over Australia's southern coastal cities (like Melbourne and Adelaide). The climatological mean of the most heatwave and severe heatwave metrics is substantially higher in recent decades compared to earlier periods across all the cities considered. The findings of our study have significant implications for the development of advanced heatwave planning and adaptation strategies.

中文翻译：

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澳大利亚热浪趋势的加剧及其对观测数据的敏感性

热浪是澳大利亚气候的惯常极端事件，可能对人类健康，农业以及城市和自然系统造成灾难性影响。我们分析了整个澳大利亚的热浪指标的趋势（频率，持续时间，强度，数量，累积强度，时间和季节持续时间）在69个延长的夏季（即，1951-1951年至2020年3月）中的趋势。我们的发现不仅强调热浪变得越来越热，越来越长，越来越频繁，而且表明它们在过热的情况下发生，开始得更早，并且在近几十年来扩展了澳大利亚许多地区的季节。自从上次进行的澳大利亚研究以来，澳大利亚的热浪趋势已经加强。我们还使用三个不同的观测产品（AWAP和SILO网格化数据集以及ACORN_SATV2台站数据）在选定时间段（1911-2019年，1911-1964年和1965-2019年）中对当地城市规模的热浪和严重热浪趋势进行了调查。结果表明，三个数据集之间的热浪趋势明显不同。但是，结果表明，最近几十年来，澳大利亚南部沿海城市（如墨尔本和阿德莱德）的严重热浪累积强度及其季节持续时间已经显着增加。与考虑的所有城市的早期相比，最近几十年来，大多数热浪和严重热浪指标的气候平均数要高得多。