Due to the COVID-19 pandemic, populations from many countries have been confined at home for extended periods of time in stressful environmental and media conditions . Cross-sectional studies already evidence deleterious psychological consequences, with poor sleep as a risk factor for impaired mental health . However, limitations of cross-sectional assessments are response bias tendencies, and the inability to track daily fluctuations in specific subjective experiences in extended confinement conditions . In a prospective study conducted across three European countries, we queried participants (N = 166) twice a day through an online interface about their sleep quality and their negative psychological experiences for two consecutive weeks . Focus was set on between-and within-person associations of subjective sleep quality with daytime experiences such as rumination, psychotic-like experiences, and somatic complaints about the typical symptoms of the coronavirus . Results show that daily reports of country-specific COVID-19 deaths predicted increased negative mood, psychotic-like experiences and somatic complaints during the same day, and decreased subjective sleep quality the following night . Disrupted sleep was globally associated with negative psychological outcomes during the study period, and a relatively poorer night of sleep predicted increased rumination, psychotic-like experiences, and somatic complaints the following day . This temporal association was not paralleled by daytime mental complaints predicting relatively poorer sleep quality on the following night . Our findings show that night-to-night changes in sleep quality predict how individuals cope the next day with daily challenges induced by home confinement.