Climate change is aggravating water scarcity worldwide. In rural households lacking access to running water, women often bear the responsibility for its collection, with adverse effects on their well being through long daily time commitments, physical strain and mental distress. Here we show that rising temperatures will exacerbate this water collection burden globally. Using fixed-effects regression, we analyse the effect of climate conditions on self-reported water collection times for 347 subnational regions across four continents from 1990 to 2019. Historically, a 1 °C temperature rise increased daily water collection times by 4 minutes. Reduced precipitation historically increased water collection time, most strongly where precipitation levels were low or fewer women employed. Accordingly, due to warming by 2050, daily water collection times for women without household access could increase by 30% globally and up to 100% regionally, under a high-emissions scenario. This underscores a gendered dimension of climate impacts, which undermines womens’ welfare.