Climatological features of observed annual maximum hourly precipitation have not been documented systematically compared to those on daily timescales due to observational limitations. Drawing from a quality-controlled database of hourly records sampling different climatic regions including the United States, Australia, the British Isles, Japan, India and peninsular Malaysia over the 1950–2016 period, we examined climatological features of annual maximum precipitation (AMP) across timescales ranging from 1-hr (AMP_1−hr) to 24-hr (AMP_24−hr). Our analysis reveals strong relations between the magnitude of AMP and the climatological average annual precipitation (AAP), with geographic variations in the magnitude of AMP_24−hr across topographic gradients not evident in AMP_1−hr. Most AMP_1−hr are found to be embedded within short-duration storms (>70% of AMP_1−hr are embedded within 1–5 h storms), especially in regions with low AAP and in the tropical zone. Likewise, most AMP_24−hr are found to be the accumulation of a very limited number of wet hours in the 24-h period (>80% of AMP_24−hr are due to storms lasting <15 h) across many parts of the sampled regions, highlighting the added-value of hourly data in estimating the actual precipitation intensities. The seasonal distribution of AMP may change across different timescales at a specific location, reflecting the prevalence of different seasonal triggering mechanisms. We also find that most AMP_1−hr occur preferentially in late afternoon to late evening, slightly later than the usual mid-to-late afternoon peak in the mean precipitation intensity. Finally, analysis of atmospheric instability, realized through the convection available potential energy (CAPE), reveals that CAPE is higher before AMP_1−hr with respect to AMP_24−hr, although the response of precipitation intensity seems to saturate at higher CAPE levels, a feature evident both in the tropical and extratropical zones. This study provides insights on climatological features of hourly precipitation extremes and how they contrast with the daily extremes examined in most studies.

由于观测的局限性，与每日时间尺度上相比，没有系统地记录到观测到的年度最大每小时降水量的气候特征。从每小时记录的质量控制数据库中抽取1950-2016年期间采样的不同气候区域（包括美国，澳大利亚，不列颠群岛，日本，印度和马来西亚半岛），我们研究了整个地区的年最大降水量（AMP）的气候特征。时间范围从1小时（AMP _1-hr）到24小时（AMP _24-hr）。我们的分析揭示了AMP的大小与气候平均年降水量（AAP）之间的密切关系，而AMP _24-hr的大小却存在地理差异跨地形梯度在AMP _1-hr中不明显。发现大多数AMP _1-hr嵌入短时暴风雨中（> 70％的AMP _1-hr嵌入1-5小时暴风雨中），尤其是在AAP较低的地区和热带地区。同样，发现大多数AMP _24-hr是_24小时内非常有限的湿润时间的累积（> AMP _24-hr的80％这是由于在采样区域的许多地方持续了<15小时的暴风雨，突出了每小时数据的附加值，以估算实际的降水强度。AMP的季节性分布可能在特定位置的不同时间尺度上发生变化，反映了不同季节触发机制的普遍性。我们还发现，大多数AMP _1-hr优先发生在下午晚些时候至傍晚，比平均降水强度的通常中午到下午稍晚一些。最后，通过对流可用势能（CAPE）实现的大气不稳定性分析表明，相对于AMP _24-hr，CAPE在AMP _1-hr之前更高，虽然降水强度的响应似乎在较高的CAPE水平下达到饱和，但在热带和温带地区均很明显。这项研究提供了关于每小时降水极端值的气候特征及其与大多数研究中所检查的每日极端值的对比的见解。