Worldwide school closures and remote learning have been implemented during the COVID-19 pandemic. These measures' impact on young populations' academic achievements is unclear. This study (N = 1,736, ages 14-20 years, 53% female, and Chinese) analyzed academic examination scores for students at a high school in Eastern China between January and July 2020. Results showed that overall, students' academic achievements appeared to be negatively affected amid a school closure. More importantly, students' self-control was introduced as a moderating factor that partially accounted for this difference in the context of remote learning at home. These findings extended our understanding of school closures' unequal impact on young populations. Education and social policies should respond to these challenges during times of crisis.