A significant reduction in summer monsoon rainfall has been observed in northern central India during the second half of the twentieth century, threatening water security and causing widespread socio-economic impacts. Here, using various observational data sets, we show that monsoon rainfall has increased in India at 1.34 mm d⁻¹ decade⁻¹ since 2002. This apparent revival of summer monsoon precipitation is closely associated with a favourable land–ocean temperature gradient, driven by a strong warming signature over the Indian subcontinent and slower rates of warming over the Indian Ocean. The continental Indian warming is attributed to a reduction of low cloud due to decreased ocean evaporation in the Arabian Sea, and thus decreased moisture transport to India. Global climate models fail to capture the observed rainfall revival and corresponding trends of the land–ocean temperature gradient, with implications for future projections of the Indian monsoon.

在20世纪下半叶，印度中北部观测到夏季季风降雨量大大减少，这威胁到水的安全并造成广泛的社会经济影响。在这里，利用各种观测数据集，我们表明，季风降雨在1.34毫米d在印度增加^-1 十年^-1自2002年以来。夏季季风降水的这种明显复苏与有利的陆-海温度梯度密切相关，这是由于印度次大陆上强烈的变暖特征和印度洋上变慢的速率所致。印度大陆的变暖归因于阿拉伯海海洋蒸发减少导致的低云减少，从而减少了向印度的水分输送。全球气候模型未能捕捉到观测到的降雨复苏以及陆地-海洋温度梯度的相应趋势，从而影响了印度季风的未来预测。