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The Qinghai‐Tibet Plateau (QTP) plays a crucial role in regulating the climate and hydrology over Asia, and studies indicate that the QTP tends to be warm and humid as a whole. Although precipitation variability on the QTP has a great impact on floods, soil erosion, and droughts, it is poorly understood owing to sparse meteorological observations. This study has investigated the temporal variability of precipitation on the QTP and its surrounding areas on different time scales over the past 40 years using the standardized variability index (SVI) based on entropy as well as its changing trends. The results show that the variability of precipitation has different spatial patterns on different time scales. In general, the variability of both the precipitation days and amounts are low in the southeast and northwest corners of the plateau and high in the southwest and north. It was found that the number of light precipitation days in the high vegetation coverage area in the southeastern plateau decreased significantly, but increased greatly in the bare land and sparse vegetation coverage areas in the northern part of the plateau. Such changes are believed to be conducive for ecological restoration. Most importantly, in the southern foothills of the Himalayas, many light precipitation days have turned into moderate and heavy precipitation days, and a significant increase in annual precipitation has also been noted, which are likely to cause natural disasters considering the local topographical conditions, such as landslides and mudslides. Highlights: In QTP, SVIME in May is closer to summer mode, indicating monsoon beginning have advanced to May.Extreme precipitation significantly influences precipitation variability.Daily SVIAE decreases in grassland/barren/sparsely vegetated land, good for ecology.Light rain days increased in bare land/sparse vegetation areas, benefiting vegetation restoration.In southern Himalayas, light rain changed to moderate/heavy rain, leading to natural disasters. [ABSTRACT FROM AUTHOR]

[Display omitted] • SVI is used to characterize daily precipitation variability within a month/season/month in the QTP. • Precipitation variability decreased in the areas with low vegetation coverage. • Precipitation variability may increase in the southwest of the Himalayas foothills in the future. • Sea-land thermal difference between the Indian Ocean and the QTP is highly correlated with SVI. • Influence of East/South Asian monsoons on summer precipitation variability over QTP is complementary. The Qinghai-Tibet Plateau (QTP) is a hotspot in the study of global climate change due to its profound impact on the atmospheric water cycle in Asia and even the world. Previous studies on the QTP mainly focused on the spatial distribution of precipitation and its changing trend. To investigate the temporal and spatial variations of precipitation variability on the QTP, this study applied the standardized variability index (SVI) based on entropy on its daily precipitation without any preset distribution. The results showed that for most monsoon months in the past 40 years, SVI has a significant downward trend in the southwest foot of the Himalayas and the border zone between barren and grassland areas, indicating that precipitation has become more uniform, which is beneficial for growth of grassland. However, the Hurst exponent shows that such trend will reverse in the future, which may cause natural disasters such as landslides and debris flows in the monsoon period considering the large amount of precipitation and the local topographic conditions in the southwest of the Himalayan foothills. The inducements of such precipitation variability were also studied, including Asian monsoon, westerly jets, sea-land thermal difference, and Sea Surface Temperature (SST). Compared with the monsoon index, the sea-land thermal difference has a stronger correlation with the precipitation variability. The SST anomaly closer to the east coast of the equatorial Pacific also has a great impact on the variability of precipitation over the plateau. This study contributes to understanding precipitation variability in the QTP at a sub-seasonal period. [ABSTRACT FROM AUTHOR]